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GENERAL PSYCHOLOGY 



THE UNIVERSITY OP CHICAGO PRESS 
CHICAGO, ILLINOIS 



THE BAKER & TAYLOR COMPANY 

NEW YORK 

THE CAMBRIDGE UNIVERSITY PRESS 

LONDON AND EDINBURGH 

THE MARUZEN-KABUSHIKI-KAISHA 

TOKYO, OSAKA., KYOTO, PUKUOKA, SEND A I 

THE MISSION BOOK COMPANY 

SHANGHAI 



General Psychology 



By 

WALTER S. HUNTER 

Professor of Psychology, University of Kansas 




THE UNIVERSITY OF CHICAGO PRESS 






Copyright 1919 By 
The University of Chicago 



All Rights Reserved 



Published August 191 9 



itH -i his 



Composed and Printed By 

The University of Chicago Press 

Chicago, Illinois, U.S.A. 



©CI.A529 716 



PREFACE 

To some of us the preface of a textbook is one of the most 
interesting of its features. There the author puts aside his air 
of instruction and authority, lays bare his hidden complexes, 
his morbid fears, and erects defense mechanisms against the 
many critics that of course his work must find. In the present 
instance I have adhered closely to the subject-matter and 
method which have proved successful in my own semester 
courses. I have found that students desire more than general 
formulas and principles. They are far more interested in 
accounts of experimental facts and procedures and are willing 
to leave the other for the manuals of advanced students. (The 
actual student, of course, is willing to leave it all to someone 
else, but since he must choose I find that he prefers the concrete 
facts.) The present book seeks to meet this situation and still 
remain a textbook and not become a treatise. It has been 
written in the conviction that too much stress is placed upon 
normal adult psychology (pure psychology) in our introductory 
courses. In many if not in most cases these courses are meant 
by the department and college administrations to give a com- 
prehensive view of the field as well as to furnish specific training 
in the science. This demand is not only sound from the point 
of view of culture, but it is important in the resulting view of 
the science. Psychology is far more than normal adult psy- 
chology. Yet many of its readers retain the impression that 
the chief topic is sensation and space perception. The present 
book seeks to forestall these misconceptions in the student by 
presenting a general survey of the science while still stressing 
the customary side of the subject. In my opinion this procedure 
becomes still more valuable when it is remembered that the 



vi PREFACE 

great majority of students acquire all of their technical psy- 
chology from the introductory courses. The chapters of Part I 
are not intended as complete summaries of the respective fields 
concerned. They seek rather to stress typical problems illus- 
trative of the scope of psychology. The chapter on " Animal 
Psychology" is unfortunately the least well-rounded and com- 
prehensive because much that might be written there has been 
deferred to Part II, where the topics of instinct, habit-formation, 
and association are discussed. The book is so arranged that, 
in teaching, Part I may either precede or follow Part II. Which- 
ever method is used, one is certain to see merit in the alternative 
procedure. My own experience favors the sequence as given 
in the text. To take up "Animal," "Individual and Applied," 
"Abnormal," and "Social and Racial Psychology" first is to 
secure the student's interest at once, if it can be secured, 
through a study of the very concrete and the practical. It is 
true that if these topics came last in the course they might be 
more adequately understood; but the same thing is true for 
"Normal Adult Psychology," with the added reason that 
practically a teacher is so hurried at the close of the semester 
that topics left for the last are often slurred over and telescoped. 
In using the material of Part I in a semester course I have 
contented myself with assigned readings and approximately two 
lectures on each chapter. This can be elaborated more fully 
in longer courses, and in shorter courses Part I can be used as 
outside reading matter with Part II the subject for lecture. 

From the theoretical standpoint our position is one of a 
combination of behaviorism and structuralism. I see no need 
for forcing the subject-matter into one or the other mold. 
Neither is large enough alone. Psychologists study both con- 
sciousness and behavior that does not involve consciousness. 
Functionalism seems untenable unless one assumes that mind 
affects the body. It played its great role by stressing biological 
factors until behaviorism could appear upon the scene. If, on 



PREFACE vii 

the other hand, one must weigh the respective merits of struc- 
turalism and behaviorism, the latter I think has the advantage. 
Our problem, however, is not so much to state everything in 
objective (behavioristic) terms as it is to supplement the intro- 
spective account with data upon environmental adjustments 
irrespective of the conscious qualitative content. It is well and 
important to know that such and such an act of reasoning, of 
delusion, etc., can go on in terms of auditory images or of 
kinaesthetic sensations; but it is of far more value to analyze 
the process of success or failure. 

It is a pleasure to acknowledge the influence upon this book 
of the teaching of Professors James R. Angell, Harvey Carr, 
and John B. Watson, and of the writing of Professors James and 
Titchener. My wife, Alda Barber Hunter, has given most 
valuable aid in the actual preparation of the manuscript. 

Permission to reproduce illustrations has been kindly 
granted by the following: The Macmillan Co., E. B. Titche- 
ner, and H. H. Goddard; Lea & Febiger; Wm. Wood & Co.; 
P. Blakiston's Son and Co.; C. H. Judd; G. P. Putnam's 
Sons; the Rebman Co.; W. B. Saunders Co. and C. J. Her- 
rick; the Wistar Institute of Anatomy and Irving Hardesty; 
Journal of Animal Behavior, F. S. Breed and J. F. Shepard; 
Henry Holt & Co. ; the Psychological Review Co., J. B. Watson, 
R. M. Yerkes, and W. L. Bryan; and the C. H. Stoelting Co., 
makers of psychological apparatus. 

Walter S. Hunter 

Lawrence, Kansas 
May i, 1919 



TABLE OF CONTENTS 

INTRODUCTION 

The Subject-Matter of Psychology. The Nature of Behavior. 
The Nature of Consciousness. The Methods of Psychol- 
ogy. The Fields of Psychology. References. 

PART I. FIELDS OF PSYCHOLOGY 

CHAPTER PAGE 

I. Animal Psychology 13 

Introduction. The Chief Problems. Methods of Ex- 
perimentation. Tropisms. Instincts. Sensory Pro- 
cesses. Studies on Habit- Formation. Imitation. The 
Delayed Reaction. Conclusion. References. 

II. Individual and Applied Psychology . . . . $6 

I. Individual Psychology: 

Introduction. The Binet-Simon Scale. Criticisms 
of the Binet-Simon Scale. Performance Tests. The 
Calculation of Mental Age. Group-Examination 
Methods. The Feeble-minded. The Inheritance of 
General Intelligence. The Use of Statistical Methods. 

II. Applied Psychology: 

Psychology in Its Relation to Medicine and Law. 
The Relation of Psychology to Education. Psychology 
and Business. Conclusion. References. 

III. Abnormal Psychology .61 

Problems. Defense Mechanisms. Types of Mental 
Disease. Causes of Nervous and Mental Disease. 
Paresis. Paranoia. Multiple Personality. Hysteria. 
Freud's Conception of the Neuroses. The Psycho- 
analytic Method. References. 

ix 



x TABLE OF CONTENTS 

CHAPTER PAGE 

IV. Social and Racial Psychology 84 

I. Social Psychology: 

General Problems and Points of View. The Nature 
of Society. The Origin of Society. 

A. The Self as Social: The Place of Instincts in Social 
Life. Socializing Influences in the Individual — 
1. Sympathy. — 2. Imitation. — 3. Suggestion. The 
Nature of the Self. The Development of the Self. 
Baldwin on the Growth of the Self. 

B. Social Institutions : Introduction. The Nature of 
Custom. The Mob. 

II. Racial Psychology: 

Racial Differences in General Ability. Resume of 
Part I. References. 

PART II. NORMAL HUMAN ADULT PSYCHOLOGY 

CHAPTER PAGE 

I. Attention 113 

Attention and Selection. Selective Agencies. Anatomi- 
cal Conditions. Objective Conditions. Subjective 
Conditions. Accurate Attention. Further Specific Prob- 
lems in Attention. The Scope of Attention. The Dura- 
tion and Fluctuation of Attention. Classes of Attention. 
Motor Accompaniments. References. 

II. The Nervous System 132 

The Reasons for Study. The Neurone. The Reflex Arc. 
The Development of the Nervous System. Divisions of 
the Adult Nervous System. The Structure and Func- 
tion of the Spinal Cord. The Medulla. The Cerebel- 
lum. The Mid-Brain. The Thalamus. The Cerebral 
Cortex. The Cranial Nerves. Important Groups of 
Conduction Paths. References. 



TABLE OF CONTENTS xi 

3APTER PAGE 

III. Reflex Action and Instinct 158 

Introduction. Definition of Reflexes. Types of Reflexes. 
Typical Phenomena in Reflex Action. Resulting View of 
Behavior. Definition of Instincts. Some Experimental 
Studies of Instinct: — 1. The Pecking of Chicks. — 2. The 
Instinct for Vocalization in Birds. The Permanent Char- 
acter of Instincts. The Modification of Instincts. The 
Origin of Instinct. Historical Theories of the Origin of 
Instinct. The Classification of Instincts. Instinct and 
Intelligence. Habit. References. 

IV. The Emotions 179 

Introduction. The James-Lange Theory of Emotion. 
Criticism of the James-Lange Theory. Sherrington's 
Experiment with Dogs. Cannon on Bodily Disturbances 
in Pain, Fear, and Rage. The Neural Basis of Emotion. 
Present Status of the James-Lange Theory. Principles 
Underlying Emotional Disturbances. Classification of 
Emotions. Simple and Complex Emotions. Aesthetic 
Emotions and Empathy. Mood and Temperament. 
Sentiment. The Function of Emotions. References. 

V. The Affective Processes 200 

Introduction. Attributes of Affective Processes. Affec- 
tion and Sensation. Stimuli for Affective Processes. 
Stimuli from Art. Bodily Changes in Affection. Affect- 
ive Memory. Functions of Affection. References. 

VI. Sensory Processes 215 

Introduction. Definition of Sensory Processes. Sensa- 
tion, Perception, and Apperception. The Development 
of Sensory Processes with Experience. The Nature of 
Meaning. The Classification of Sensations — 1. Proprio- 
ceptors. 2. Intero-ceptors. 3. Extero-ceptors. Sen- 
sory Qualities. Taste. Smell. Cutaneous Sensitivity. 
Kinaesthetic and Organic Sensations. References. 



xii TABLE OF CONTENTS 

CHAPTER PAGE 

VII. Sensory Processes (Continued) 240 

Auditory Sensations. Stimuli and Receptors. Theories 
of Hearing. Certain Problems in Audition. Visual Sen- 
sations — Visual Receptors. Visual Qualities. Color- 
Mixture and Complementary Colors. Simultaneous 
Contrast and After-images. Peripheral Vision. Color- 
Blindness. Twilight Vision. Theories of Visual Quali- 
ties. Specific Nervous Energy. Sensation Intensities, 
Weber's Law. The Awareness of Space. Tactual 
Space. Auditory Space. Visual Space. Functions of 
Sensory Processes. References. 

VIII. Imagination and the Sequence of Experiences. . 277 

I. Imagination: 

The Image and Sensation. The Neural Basis of 
Imagery. Image-Types. Productive and Reproductive 
Images. The Function of Images. 

II. The Sequence of Experiences: 

The Sequence of Images and Sensations. The Laws 
of Association. The Neural Basis of Association. 
Secondary Laws of Association. Total and Focalized 
Recall. Simultaneous Association. References. 

IX. Memory . . ' . . 294 

Definition. Memory and Imagination. Recognition. 
Experimental Studies of Recognition. The Problems of 
Retention. Conditions Favorable to Learning. Learn- 
ing Significant versus Nonsense Material. Remote 
Associations. Habit-Interference. Transfer of Training. 
Effects of Practice and Intention. The Whole versus 
the Part Method. Distribution of Effort. The Training 
and Economy of Memory. Nature of Forgetting. Rate 
of Forgetting. "The Fixation of Arcs in Habit." 
Curves of Learning. The Function of Acquired Modi- 
fications of Behavior. References. 



TABLE OF CONTENTS xiii 

CHAPTER PAGE 

X. Thinking 320 

Introduction. The Nature of the Concept. The Forma- 
tion of Concepts. Values and Limitations of Concepts. 
The Nature of Judgment. Experimental Studies of 
Judgment. The Absolute Impression. The Role of the 
Image in Judgment and Thinking. The Conscious 
Attitude. The Aufgabe. Analysis of a Concrete Act of 
Thought. The Role of the Syllogism in Thought. 
Deduction and Induction. References. 

Author Index "..... 345 

Subject Index 348 



INTRODUCTION 



INTRODUCTION 

The Subject-Matter of Psychology. — At present attempts 
to delimit psychology from the other sciences are rarely made 
with particular seriousness. It is enough to get clearly in mind 
the general goal to be attained. No growing field of study can 
be held within the limits of a definition, for it will go wherever 
its devotees take it ! Psychology has always taken as its general 
goal the understanding of human nature and human behavior. 
Until the middle of the nineteenth century chief emphasis was 
placed upon the intellect, and psychology was considered a part 
of philosophy particularly as related to the problems of the 
theory of knowledge. As such it "was the study of mind, con- 
sciousness, or the soul, and the limits of these marked the 
uttermost boundaries of the science. In 1830 and the years 
following, however, genuine scientific movements in psychology 
had their beginnings in Germany, France, and England. In 
Germany the work was begun by physiologists and physicists, 
Ernst Weber, Theodor Fechner, Hermann Helmholtz, Ewald 
Hering, and Wilhelm Wundt. In France the emphasis was 
upon the study of abnormal mental phenomena. The typical 
students were J. M. Charcot, Pierre Janet, and Alfred Binet. 
In England we find yet another type of work in the biological 
studies of the behavior of man and other animals carried on by 
Charles Darwin, Herbert Spencer, G. J. Romanes, and others. 
From these early beginnings first one phase of human experience 
and then another has come under experimental scrutiny until 
in the past decade the chief contributions have concerned the 
nature of thinking and the measurement of "general intelli- 
gence" in the various grades of men. With the development 
of the science has come an increasingly important bearing upon 



4 GENERAL PSYCHOLOGY 

the practical problems of society, many phases of which will 
become apparent as our present account proceeds. 

It is possible to divide the subject-matter of psychology 
into two significant classes: the facts of consciousness and the 
facts of behavior. These two groups of phenomena are most 
closely related, as we shall see, and yet they are so distinct that 
separate theoretical systems of psychology have been founded 
upon them, each denying the possibility of the other. The 
present account should make clear that the science of psy- 
chology, as it is actually developing in the laboratories, involves 
both classes of data. 

The Nature of Behavior. — Our introductory account of 
behavior may well be brief. By behavior is meant the muscular 
and glandular activity of an organism, such, for example, as is 
seen in fear, in the formation of habits of movements, in speak- 
ing, etc. Psychologists study behavior of this type and also 
such behavior as the variations in breathing and circulation 
which accompany conscious states of the type of pleasantness, 
unpleasantness, and attention. Mention should also be made 
of the important behavior studied in relation to emotions 
(e.g., the activity of glands of internal secretion) and in rela- 
tion to hunger (the contractions of the stomach), and of the 
nature of the nervous processes which control all of them. In 
the study of these topics psychology comes in the closest possible 
relation to physiology, zoology, and neurology, just as it is 
closely related to physics in the study of light and sound. 
However, not all forms of behavior are studied by psychologists. 
There are some which have only an indirect and very distant 
relation to the consciousness of the individual, such, for example, 
as the secretion of pancreatic juice and the mechanics of respira- 
tion, and which have also but little effect upon the overt behavior 
of the organism as a whole. These topics may therefore be 
termed purely physiological, and will remain so until evidence 
is advanced indicating a relatively intimate connection with 



INTRODUCTION 5 

consciousness and the organic behavior of the individual, the 
overt behavior of the organism as a whole. 

The Nature of Consciousness. — By a state of consciousness 
we shall understand anything of which I am immediately aware — 
a book, a table, a color, a pain, my hate, a joy, a memory, or 
a thought. On the other hand, no object of which I am at 
present unaware is a state of consciousness. Into this class 
fall things I have never known immediately and also those 
objects that I have known but of which I am not now aware, 
such as forgotten pictures and emotions. Every state of con- 
sciousness must exist in the present; what is past or future is 
non-existent. A forgotten idea does not exist stored up in 
the mind: it is the modifications in the nervous system that 
remain. 

Things as we experience them depend upon the activities 
of the sense-organs and of the nervous system and not solely 
upon the physical object. Thus a room may be hot to one 
person and cold to another, depending upon whether or not the 
individual has just come from a warmer or a cooler room. Again 
a person walking toward us is actually affecting the eye as 
though he were steadily growing larger, and yet what we are 
aware of is a decrease in distance. These are facts of conscious- 
ness, as is also the sort of mental imagery one uses in thinking 
of a familiar house, whether one has a mental picture or an 
auditory image of its name. 

Consciousness accompanies certain forms of activities in the 
nervous system. It is, however, not a nervous process, nor 
is it located in the brain. What science finds in the brain are 
certain physical and chemical processes, all of which are as 
different from a state of consciousness such as joy as two exist- 
ing facts can be. The further description of consciousness must 
await the development of the body of the present text. 

The Methods of Psychology. — The primary methods of 
psychology are not different from those of other sciences which 



6 GENERAL PSYCHOLOGY 

require the analytical, experimental observation of facts and 
events that are vivid and precise at one time though very 
fleeting and elusive at another. The observation and descrip- 
tion of states of consciousness are difficult and require thorough 
training before expertness can be attained — a condition, how- 
ever, that is true of the task required of observers in all sciences 
and in many branches of non-scientific life. An umpire, e.g., 
in a baseball game must be able to see instantly where the ball 
has gone and whether or not it gets to first base prior to the 
runner. So the psychologist must say which of two events 
precedes and what each one is. If they are sensations — things 
seen, touched, smelled, etc. — the task may be relatively easy. 
If they are ideas the difficulty may be very great. Many 
states of consciousness, such as memories, images, feelings of 
pleasantness and unpleasantness, are not only vague and con- 
fused, but are also fluctuating in character. We can attend 
to them for a moment, and then they are gone. The difficulty 
of accurate observation and report is certainly real, but it is 
not different in kind from that which meets the histologist and 
zoologist. When they put structures living or dead under the 
microscope and attempt to describe what is seen, the lines of 
demarcation are often faint or the activities of the organism 
brief, with the result that contradictory evidence is presented 
by different observers. The solution of the problem then comes 
only with increased training in observation and with many 
repeated descriptions, a condition similar to that presented to 
the psychologist. 

The experimental work in psychology consists in so con- 
trolling the factors modifying consciousness and behavior — for 
example, vision and habit-formation — that accurate statements 
can be made concerning the causes of various features of these 
two classes of material. This may mean in the former case 
the control of the amount, size, and duration of illumination 
and in the latter case the regulation of the complexity of the 



INTRODUCTION 7 

habit and of the number of trials per day. These observations 
must be systematic, controlled, and subject to repetition if 
they are to meet the requirements of science. 

The particular experimental methods that are used in psy- 
chology will vary with the particular problems to be studied, 
as is the case in physics, chemistry, and zoology. In our present 
science there are, for example, the methods of mental tests, of 
psychoanalysis, of psychophysics, of animal behavior, etc. 
These methods will vary as much for the different problems 
within one science as they do from one science to another. It 
should be insisted that there is no one method peculiar to psy- 
chology. It is often urged that introspection is such a method. 
Introspection, when so used, signifies a booking within" and 
a "noting of the nature of one's conscious states," as opposed 
to a "looking outward" and a "noting of external things," 
which is termed observation. The assumption is here that 
consciousness is in some manner "within." We have said, 
however, that consciousness is not in the brain, and observation 
fails to verify the "inward" as opposed to the "outward" exist- 
ence of such states of consciousness as colors, sounds, etc. Con- 
scious states may be localized outside the body, as is here the 
case, or they may be within the body, as is true in hunger and 
anger. As a result of this possible twofold location of con- 
sciousness, the exact use of the term introspection only produces 
confusion. When met in the present text, therefore, the term 
will be synonymous with observation, for one need not have 
two scientific methods merely because the material that one 
studies may be located in either of two places. 

The Fields of Psychology. — Although present-day psychol- 
ogy is concerned with the general problems of consciousness and 
behavior, there are a sufficient number of different conditions 
under which the problem must be studied to justify the division 
of the science into separate fields. These may be enumerated 
as follows: normal human adult psychology, animal psychology, 



8 GENERAL PSYCHOLOGY 

social and racial psychology, individual and applied psychology, 
and abnormal psychology. In addition to these, child psy- 
chology, genetic psychology, and physiological psychology are 
often mentioned. These, however, in our opinion do not 
deserve to rank as separate fields or divisions of the science. 
Practically all that is known about child psychology is the 
result of mental tests. The remainder of the work which has 
been done (observations, usually uncontrolled, on instinctive 
development) may well be included with the tests in individual 
psychology. Genetic psychology is not so much a field as a 
point of view from which data are arranged according to a scale 
of complexity or of probable development — that is, we arrange 
the facts of animal, child, and adult human behavior in a series 
to indicate their probable order of appearance. Finally, all 
psychology seeks to correlate consciousness and physiological 
processes and is therefore physiological psychology in intent. 
The more all of these parts of general psychology develop the 
more thoroughly interrelated they become with our ultimate 
purpose, that is, the giving of a complete account of human 
nature. On the basis of this developing body of scientific data, 
a psychotechnique (Miinsterberg's term) is growing up which, 
in addition to contributing purely scientific material, is aiding 
materially in the solution of many social problems. We shall 
include certain so-called practical material in the chapters that 
are to follow. 

A more detailed view of the present status of the various 
fields of psychology, with their special methods of investigation, 
will be given in Part I, "Fields of Psychology." The discussion 
of normal human adult psychology, however, will be reserved 
for Part II, in that this field is usually treated as the major part 
of psychology. Historically it is the parent stock. At the 
present time, however, when judged by the central problem of 
the science as a whole, it has several rivals among the other 
fields both with respect to exuberancy of spirits and to impor- 
tance of contributions. 



INTRODUCTION 9 

REFERENCES 

Angell, James R. Some Chapters from Modern Psychology. New 

York: 191 2. 

. An Introduction to Psychology. New York: 191 8. 

Breese, B. B. Psychology. New York: 191 7. 

Dunlap, K. Psychobiology. Baltimore: 1914. 

James, Wm. Principles of Psychology, 2 vols. New York: 1890. 

Klemm, Otto. A History of Psychology. Trans, by Wilm and 

Pintner. New York: 1914. 
Miinsterberg, Hugo. Psychology, General and Applied. New York: 

1914. 
Stout, G. F. Manual of Psychology. Third edition. London: 1913. 
Stratton, G. M. Experimental Psychology and Culture. New York: 

1903. 
Strong, C. A. Why the Mind Has a Body. New York: 1903. 
Titchener, E. B. Text-Book of Psychology. New York: 191 1. 
Yerkes, R. M. Introduction to Psychology. New York: 191 1. 



PART I. FIELDS OF PSYCHOLOGY 



CHAPTER I 
ANIMAL PSYCHOLOGY 

Introduction. — The psychology of the last fifteen years has 
been particularly characterized by the growth of the objective 
point of view. This angle of approach to the subject-matter 
of the science places chief emphasis upon the behavior of the 
individual and less upon his consciousness. It is much too early 
to decide between the two points of view. Indeed it is impos- 
sible to say whether the objective method has only broadened 
the science of psychology or whether the advance has been so 
great as actually to create a new science which still masquerades 
under the name psychology. It is clear, however, that in the 
advance two particular fields have led the way, animal psy- 
chology and individual psychology. We shall treat the latter 
in the following chapter. 

Animal psychology, or animal behavior as it is now usually 
termed, cannot deal with consciousness save inferentially be- 
cause the animals studied cannot introspect and consequently 
cannot tell us their experiences. This field is therefore the 
objective psychology par excellence. The descriptive terms 
that are used in treating behavior, such as sensation, memory, 
imitation, etc., since they are largely borrowed from human 
psychology and common sense, do have a marked reference to 
conscious states, but this fact should either be ignored or treated 
in a hypothetical manner. We need not attempt to decide the 
question whether or not animals are conscious. They may or 
may not have a mental life approximately similar to that of man. 
Certain it is that there are no evidences or criteria by which we 
may decide that consciousness is or is not present in animals 
below man. Although the animal's brain, sense-organs, and 

13 



14 GENERAL PSYCHOLOGY 

behavior may closely approximate man's, still we cannot tell 
that neural action has crossed the threshold of consciousness. 
We do not know even in man actually what brain activity is 
necessary for the appearance of consciousness, because not all 
brain processes condition it. We shall therefore leave aside 
all questions concerning the existence and nature of an animal 
mind and seek a brief introduction to the problems of animal 
behavior. Here we shall be interested in all reactions of a 
particular organism as a whole upon its environment. We 
shall attempt to draw no sharp line of distinction between be- 
havior of a part and behavior of the whole animal, organic 
behavior; and yet the emphasis will be clearly on the side of the 
latter problem. Interest in this field is largely due, historically, 
to the influence of Darwin, Romanes, C. Lloyd Morgan, and 
the host of naturalists who studied the problem of animal 
behavior after the scientific advent of the theory of evolution. 
The Chief Problems. — The field of animal behavior divides 
itself into three great topics, the last two of which can really be 
considered one: (i) the study of sense-organ processes — what 
an animal can see, hear, taste — and the functions of these 
processes in the organism's daily behavior; (2) the study of 
motor and glandular activity — instincts, reflexes, and habits; 
(3) the study of the higher capacities, as they may be called 
for convenience — imitation, ideational behavior, language 
capacities, and the general problem of whether animals think. 
Under the second division we have the question of learning, its 
conditions, and types. I may anticipate enough to say that 
the results obtained here are essentially true for man. The 
topics under the third division are really parts of the study of 
habit, for each of these "higher activities" is either a method 
or condition of habit-formation or a particular way of utilizing 
the habits when once established. Since, however, the topics 
here listed are usually associated with so-called higher mental 
ability, it would not be representative of the status of the science 



ANIMAL PSYCHOLOGY 15 

to classify them without further ado under the caption motor and 
glandular activities. 

As a result of the exhaustive study of the above topics, there 
will accrue at least the following results: (1) Psychology as a 
whole will become more objective. (2) The essential continuity 
of human and animal sensory and motor activities (including in- 
stincts and habits) will be seen. (3) Light will be thrown upon 
many aspects of human nature which can be more safely and 
conveniently studied upon animals than upon man. (4) New 
points of view concerning human processes — learning, asso- 
ciation, ideas, etc. — will arise which will be helpful in normal 
human studies. Much of this is possible because animal psy- 
chology is still young enough or different enough to resist tend- 
encies toward the formation of systems of psychology, a practice 
which has beset the parent subject. 

Methods of Experimentation. — For practical purposes we 
may say that there are three chief methods of studying animal 
behavior: (1) the naturalistic method, or method of field 
observation; (2) the method of general response; and (3) the 
method of selective response. The first method was used 
particularly by the naturalists of Darwin's day. It is still used 
for practically the same purpose, viz., for the observation of the 
animal in his own habitat, unmolested by experimental condi- 
tions. The studies in this field of work cover such topics as 
the "expression of emotions" in animals (Darwin) and the 
general observations on instincts, such as migration, mating, 
homing, and fighting (Romanes, Morgan, Watson, and innu- 
merable others) . This method has its chief value for psychology 
in that it suggests many problems for accurate study, for 
unaided by experiment it can give us little concerning sense- 
organ activities or concerning the genesis of types of action. 
If a vulture approaches a heap of carrion, or if an owl catches 
a mouse, field observation can record the fact, but it cannot 
tell what sense-organs are involved. Did the vulture smell or 



1 6 GENERAL PSYCHOLOGY 

see his food? Did the owl see, hear, or smell the mouse? Only 
careful experiments upon the sensitivity of the animals con- 
cerned can give the answer. The same thing is true with respect 
to the nature and place of imitation and "reason" in animals. 
Field observations have constantly and insistently recorded 
phenomenal performances which are held to demonstrate the 
presence of these powers. Experimentation, however, has 
practically always either reversed the facts or shown the use- 
lessness of such interpretations. 

The method of general response applies typically to those 
cases in which the experimenter confronts an animal with a 
certain stimulus or object and notes its general, untutored, 
native response. Francis Galton was a prominent pioneer in 
the use of this method. Going through the zoological gardens 
of London, he sounded high-pitched notes on a whistle, which 
he carried concealed in his hand, near various species of animals. 
If the animal tested responded with any movements, Galton con- 
cluded that it could hear the tone in question. When carefully 
applied this method gives conclusive results on the question 
of mere sensitivity, but it is not so safe where discrimina- 
tions between objects are involved. Unless, for example, the 
experimenter can secure one kind of response to sound and 
another kind to light, there is no way of telling whether or not 
these two forms of stimulation are different for the animal. 
Work on general responses has been done particularly in studies 
of hearing, smell, and taste in fish (Parker, Zenneck, Bernoulli). 

The most important form of this method is that of condi- 
tioned reflexes perfected by Pawlow and von Bechterew. It has 
been used successfully in this country by Watson and his stu- 
dents, both on man and animals. The essential features of the 
procedure are as follows: Certain stimuli will without training 
arouse certain motor and glandular activities, e.g., taste will 
arouse a flow of saliva; increased light intensity will cause a 
contraction of the pupil of the eye; and pain will produce a 



ANIMAL PSYCHOLOGY 



17 



withdrawal of the part of the body injured. These activities 
are unconditioned reflexes. Certain other stimuli which do not 
naturally arouse the response will finally come to do so if they 
are associated frequently with the effective stimuli. Thus, 
saliva may flow from the sight of food or from the description 
of food, and we may jerk our hand back upon the appearance 
of an idea of a painful object. It will be seen that the method 




Fig. i. — The Pawlow salivary reflex method (after Yerkes and Morgu- 
lis). Saliva flows from the dog's cheek through the tube, drops down 
upon a lever, and then flows into a graduated glass. This saliva, falling 
upon the lever, causes it to vibrate and accordingly to transmit the motion 
to the marker which records on the rotating drum. The flow of saliva in 
the graduate can be measured in quantity and then chemically analyzed. 

takes account of the fact that one of the fundamental ways in 
which modes of action are varied is by changing, not the activity 
proper, but the stimuli which arouse it. Undue novelty has 
been attached to the method because most studies have been 
carried out upon the salivary reflex and upon simple protective 
reflexes, such as the withdrawal of the foot or the hand from 
pain, whereas all cases of habit-formation, learning, are equally 
true cases of the acquisition of conditioned reflexes. Figure 1 
indicates the salivary method applied to dogs. By presenting 



18 GENERAL PSYCHOLOGY 

a sound, a light, a taste, etc., with food, it can be shown that 
if the animal is sensitive these objects will soon cause a flow 
of saliva if presented when food is absent. 

The third method — selective response — is the most widely 
used behavior method among psychologists. It involves the 
same principle of association, or habit-formation, that we found 
in the conditioned-reflex method. In the present case, however, 
the animal is taught to associate certain objects — 'Colors, sounds, 
etc. — -with movements of its entire body. For example, it may 
learn to open a box or to run through a maze when placed near 
or in such an apparatus. In these instances the fundamental 
motives employed are hunger and the avoidance of pain. The 
animals are fed only after completing a test. They are never 
starved, but are fed just enough to keep them in splendid 
physical condition. Electric shocks usually serve for the 
punishments and are given when errors are made. The prime 
desideratum for this experimental work is that the response 
required of the animal (or man) shall not be opposed to its 
instinctive nature. The details of the method will appear in 
the presentation of results which we will soon give. It is inter- 
esting to note that often the results obtained by the conditioned- 
reflex method and the selective-response method do not agree. 
Thus Zeliony, using the former method, found sensitivity to 
tones in the dog, while Johnson, Hunter, and Barber, working 
with the latter method on dogs and rats, have found no evidence 
of sensitivity. The explanation of these divergent results is not 
yet forthcoming. 

The experiments and results now to be described represent 
typical studies of various sensory and motor capacities of 
animals. They indicate how the problem of relative intel- 
ligence in man and animals must be solved. Other things 
being equal, that animal is most intelligent that can "sense" 
the most stimuli and can execute the most varied forms of 
muscular responses. 



ANIMAL PSYCHOLOGY 



19 



Tropisms. — -We shall pursue our study of the capacities of 
animals according to phytogeny, beginning with the responses 
of animals of the simplest structure. Such responses are called 
tropisms. There are many definitions of this term, but to 
avoid the controversial aspects of the matter we shall define 




Fig. 2. — A negative tropism to a chemical in amoeba (after Washburn). 
The arrows indicate the direction of movement. 




Fig. 3. — A negative tropism to contact in Paramecium (from Wash- 
burn after Jennings). 

tropisms as any inherited form of response in animals devoid 
of a nervous system. These responses are either positive or 
negative — positive if the animal approaches the stimulus, nega- 
tive if the animal avoids it. The behavior can best be described 
with the aid of Figs. 2 and 3. Figure 2 represents an amoeba 



20 GENERAL PSYCHOLOGY 

coming in contact with a drop of chemical. The response or 
tropism consists in an extension of the protoplasm at some point 
of the animal's surface. Thus the amoeba gradually avoids or 
withdraws from the stimulus drop. If, in place of a chemical, 
light be used, the amoeba may either approach the light or 
avoid it, its response depending upon conditions that need not 
concern us here. Figure 3 represents a negative response of 
the paramecium to contact. Swimming in the direction of 
arrow No. 1, the organism encountered the new and harmful 
stimulus A. Thereupon the beat of the cilia (fine hairs on the 
surface of the body) was reversed in direction, and the Para- 
mecium backed away, turning at the same time away from the 
mouth-side of its body. The beat of the cilia was now again 
reversed, and the organism again swam forward. The same 
response would be made to any injurious object. Paramecium 
reacts to favorable objects by remaining in the favored locality. 
It accomplishes this by giving the negative response whenever 
its swimming activities threaten to take it beyond the optimal 
region. 

In the simple behavior of these unicellular organisms we 
have the prototype of all higher forms of response. The 
amoeba, for example, shows sensitivity, motility, and conduc- 
tivity (the transmission of energy in some form from the point 
of stimulation to the point of response) . Subsequent evolution 
adds no new function but merely brings forth special structures 
to perform them — sense organs, muscles and glands, and nervous 
tissue. With this more complex development, organisms be- 
come sensitive to more varied stimuli, and they accordingly 
respond in more highly varied ways: i.e., they become more 
intelligent. The nervous system, whose function is the co- 
ordinating of sense-organ and motor and glandular activities, 
keeps pace with this development of sensitivity and motility. 
We shall trace its growth briefly in the chapter on "The Nervous 
System." 



ANIMAL PSYCHOLOGY 21 

There is another way in which these simple organisms 
present facts of importance. They are sensitive (with almost 
no exception) to all the classes of stimuli that affect higher 
organisms. (Accordingly, we are able to call no one sense the 
most primitive.) Tropisms are classified according to the 
stimuli that arouse them as: chemotropisms, phototropisms, 
geotropisms (responses to gravity), stereotropisms (responses 
to contact), rheotropisms (responses to water currents), etc. 
These tropisms may be either positive or negative, depending 
upon the direction of the response. Two practical cases of im- 
portance are: the positive chemotropisms, which undoubtedly 
lead bacteria to attack certain tissue, and those that result in 
the sperm finding the ovum. Furthermore, when the carbon- 
dioxide content of the blood is high the stimulation of certain 
nerve cells by the changed chemical content of the blood results 
in increased heart-beat and in increased respiratory rate. This, 
too, although occurring in man, is undoubtedly a chemotropism. 
All tropisms are innate, inherited, and apparently they offer 
the only means of activity which these simple organisms possess, 
for there is no clear evidence that unicellular organisms learn 
by experience, i.e., form habits. 

Instincts. — Our chief discussion of this topic will come in 
Part II. Here it is important to point out a few facts only. 
The term instinct refers to all forms of inherited response in 
animals having a nervous system. Inherited responses, since 
they form the behavior nucleus with which each organism starts 
its life, are the fundamental stuff upon which later experiences 
must build. In the case of the unicellular organisms, we have 
just learned that the inherited responses form the sum total of 
their behavior possibilities. In higher organisms the possi- 
bility of habit-formation is present in addition; yet these habits 
must be formed out of the materials offered through heredity 
by instincts and reflexes. Practically all of our knowledge 
concerning this original and fundamental side of animal and 



22 GENERAL PSYCHOLOGY 

human nature comes from the study of animals below man — a 
condition that is due to the greater convenience of animal 
material for study and, in many cases, to the greater definiteness 
with which the instincts manifest themselves there. Aside 
from field studies, mention may be made of Yerkes and Bloom- 
field's demonstration that kittens kill mice instinctively rather 
than as a result of imitation; of Breed's and Shepard and Breed's 
proof that the instinct of pecking in the chick is imperfect at 
first and later improves greatly with practice; and of Conradi's 
demonstration that sparrows have an instinct toward vocaliza- 
tion only, whereas the particular songs will depend upon the 
birds with whom they are raised. Detailed accounts of two of 
these studies will be given in chapter iii, Part II, where reflex 
action and instincts are more fully discussed. Studies on 
instincts and tropisms are made almost entirely by the natural- 
istic and general-response methods. 

Sensory Processes. — So far in our account of animal psy- 
chology we have commented upon problems, methods, and 
inherited forms of response. We shall now present briefly 
certain typical studies upon sensory processes and then turn 
to an account of habit-formation and other "higher capacities." 
Let us first take up the sensory processes arising from the activity 
of muscles and inner organs, kinaesthetic and organic sensi- 
tivity. These processes are usually studied by the use of an 
apparatus termed the maze. Figure 4 shows the plan of a 
maze used in the study of small animals. The animal starts at 
the entrance and must run to the food-box, in the center where 
it secures food. On the first trial the animal probably requires 
20-30 minutes, finally blundering into the food-box by accident. 
On subsequent trials the run is made in shorter and shorter time 
and with fewer and fewer errors, until the animal runs about 
2-4 feet per second (if it is a rat) and makes no deviations 
from the true path. A typical learning curve is shown in 
Fig. 5, representing the gradual elimination of errors as learning 



ANIMAL PSYCHOLOGY 



23 




Fig. 4.— The circular maze and camera lucida attachment (from 
Watson). SB, entrance; MM Z , the mirrors; L, lens; IM, image of maze 
and animal that is in it. This apparatus makes possible the accurate 
recording of the distance traversed by an animal. This is done by tracing 
on IM the path followed there by the animal's image. Such a record is 
important in showing the gradual formation of the habit. 



24 



GENERAL PSYCHOLOGY 



proceeds. Watson showed that white rats can learn this 
problem in terms of kinaesthetic (nervous impulses coming 
from the muscles, joints, and tendons) and organic sensory 
processes, sound, vision, and smell being unnecessary. After 
it has learned the problem the rat runs the maze as automati- 
cally and as surely as we go into our bedchamber in the dark, 
walk in a certain direction, reach up and touch the light. The 
response in both cases is guided by kinaesthetic sense-organs, 



I 



tl 1Z » U 



Fig. 5. — A learning curve for the Hampton Court maze, based Upon 
19 normal rats (after Watson). 



and in our case we say "we just feel how far and in which 
direction to walk." If the maze is constructed so that it can 
be shortened by taking out a section without disturbing the 
interrelations of the turns, rats that have learned the problem 
previous to the change will now run into the ends of the alleys 
and run past the proper openings, just as we would fail to reach 
the light if someone had moved it. Experiment is constantly 
showing the predominant importance for all behavior of these 
kinaesthetic processes. _Vincent^has shown that rats can 



ANIMAL PSYCHOLOGY 25 

utilize odor, contact, and vision in learning the maze if such 
differences are made sufficiently prominent. However, as the 
response becomes automatic it comes more and more under the 
control of the muscle sense, until finally the other sensory cues 
lose their function. 

A very large number of experiments have been performed 
on vision in animals, particularly by Hess, Watson, Yerkes, 
Johnson, and Lashley. The tests have been on visual acuity, 
pattern perception, and the sensitivity to white and colored 
light. Especial interest attaches to the last problem. Do 
animals see color? More accurately stated the question is: 
Do they respond to monochromatic light? The earlier work 
used colored papers as sources of light. The animal was required 
to select a certain color located irregularly relative to the other 
colors, in this manner securing its food. Evidences of color 
vision were found, which were untrustworthy, however, because 
of the many uncontrolled sources of error. Even a color-blind 
individual might have succeeded in the tests, for such papers 
differ in brightness or intensity and in amount of color reflected 
(saturation) as well as in color proper. It is particularly 
difficult to interchange the intensity differences sufficiently to 
be sure that they and not the wave-length, i.e., the color, were 
the basis of the animal's response. Suppose, for example, that 
two colors, red and green, were shown to the animal, food always 
being given when the red was selected. If the animal finally 
succeeded in choosing the red 80 per cent of the time, it might 
be because the red was the darker of the two. And no change 
that could be made in the red papers might be sufficient to make 
the red the brighter, consequently causing the animal to fail 
in its response. 

In order to secure color that would be strictly monochro- 
matic and whose intensities would be thoroughly under control, 
Watson devised the apparatus shown in Fig. 6. This apparatus 
is entirely concealed from the animal tested, who sees only the 



26 



GENERAL PSYCHOLOGY 



colors cast upon the plaster-of-Paris strips. These strips are 
at the end of a two-compartment discrimination box devised 
by Yerkes and shown in Fig. 7. The animal is introduced at 
B and must go through either alley G or R in order to return 
to A and secure food, which is given only as a reward for work 



-HTRa! 




TO ANIMAi 



Fig. 6. — Ground plan of the Watson color apparatus. The pathway 
of the light is traced from the source at L through the lenses and prism to 
the strip S 2 , where the particular color rays to be used are selected. These 
are permitted to pass and are finally brought to a focus on the plaster-of- 
Paris reflectors shown at B of the insert. The wedges Wi, W 2 , W 3 serve to 
decrease the intensity of the light. The saturation or amount of color 
can be reduced by introducing white light, as shown in the insert. 



done. If mistakes are made, slight electric shocks can be given 
through the wires in the alleys. Tests have been made with 
this apparatus on monkeys, chicks, rabbits, and rats. Although 
the actual results have varied somewhat from test to test, 
almost no evidence has been brought forward indicating that 
the animals concerned could form habits in response to stimuli 



ANIMAL PSYCHOLOGY 27 

differing only in wave-length. Recently K. S. Lashley, however, 
has secured evidence of color sensitivity in chicks which leads 
him to believe that they react to color differences quite as 
readily as to intensity differences. 

The difficulty of demonstrating color vision in animals may 
well lead us to inquire concerning the detailed procedure used 
in such experimentation. Three chief methods may be noted. 
(1) If the Purkinje phenomenon is present (see p. 261), color 




Fig. 7. — The Yerkes discrimination box described in the text. The 
plaster-of-Paris strips, circles, patterns, etc., that are to be seen and dis- 
criminated by the animal appear at G and R, presented in an irregular 
order to prevent the animal's use of position habits. 

vision almost certainly exists. This phenomenon refers to the 
fact that in light of low intensity the brightest portion of the 
solar spectrum is the yellow-green ; whereas in daylight illumina- 
tion the yellow portion of the spectrum is brightest. This 
shift in brightness value does not occur in the color-blind person, 
who sees the spectrum as a series of shades of gray. (2) Trial 
may be made to force the animal to select a red as opposed to 
a given intensity of white light when the red is the darker of the 
two. When this habit is perfectly established, the brightness 



28 GENERAL PSYCHOLOGY 

of the red is increased or the brightness of the white decreased. 
If no intensity of white, from black to pure white, is confused 
with red, the animal undoubtedly is responding to wave-length 
or color. DeVoss and Ganson have presented evidence obtained 
by a method of this type, using colored papers, which has 
indicated color-blindness in cats. (3) In the third method two 
colors, e.g., red and green, may be presented to the animal as 
we have already described. If a discrimination is set up, the 
relative intensities or brightnesses can now be reversed. A 
persistence of successful choosing during this reversal would 
indicate color sensitivity. In making such a test our labor is 
much shortened and sometimes more fruitful if we know from 
prior tests how much it is necessary to change the relative 
intensities in order to reverse their values. There are many 
difficulties peculiar to the foregoing tests, but they must be 
passed over. 

Studies on Habit-Formation. — We must turn now from 
cases of sensory discrimination to problems of habit-formation. 
Here we shall gain an insight into problems of behavior as 
presented by animals, which will continue to concern us, in 
man, throughout the book. In the first of our chapter we 
commented briefly upon the original modes of acting-instincts. 
Here, on the other hand, we are to consider certain phases of 
derived or habitual behavior. The studies on habit-formation 
are studies of learning and forgetting. It is very important 
to know what the laws of learning are and how conditions may 
best be adapted to secure the highest efficiency. Is it more 
economical to give one trial a day, or two, or three? Should 
one learn a task in parts or should one learn it as a whole, if 
economy of effort is to be secured? Does learning ability vary 
with sex and age? Do habits interfere with each other, and 
can efficiency in one task improve ability in another (transfer 
of training)? How does loss of retention proceed? Is it most 
rapid at first and slower toward the last? These and many 



ANIMAL PSYCHOLOGY 29 

other problems of great practical value can be answered as well 
or better by tests upon animals than by tests upon humans, for 
with animals we more readily control motives, prepossessions, 
and modes of living, and we can also secure more convenient 
material. 

In Fig. 8 are summarized the data obtained by Ulrich with 
white rats tested to determine which favored economical learn- 
ing the most — 1, 3, or 5 trials daily. The tests required the 



„„., nn m rn en r etB n a 

ONE 11 U 10 20 28 32 35 37 3» 41 

TRIAL 

n rnn Efa HTH i 



D MALES 
U M itl^ l I j 171 m FEMALES 

TKIALS 





n n rbi m 
























ONE 
TRIAL 


11 13 1017 20 


n 


28 32 35 37 39 11 


s 


n 




pi H pi h n 












THREE 
TRIALS 




21 


30 33 38 


a 


18 




63 60 08 72 75 


















H 


n 


171 


n 


H 171 El [71 


n 


n 


171 


n 


n 



15 60 65 60 « 70 



Fig. 8. — Results secured by Ulrich on the efficiency of distributed 
effort. The figure is further described in the text. 

rat to lift a latch in order to enter a box and secure food. The 
rat was said to have learned the problem when it ran to the box 
and lifted the latch in a minimum time. From the curves, 
which record both the number of trials and the number of days 
required to perfect the habits under the several conditions, the 
general conclusion can be drawn that the less frequent the trials 
the fewer trials but the more days are required for learning. 
Which method is the more economical will depend upon the 
value one wishes more to conserve, time or trials. 1 

Evidence that certain habits may aid or hinder the forma- 
tion of other habits (cases of the transfer of training and of 

1 For a further discussion of economical learning see chap, ix, p. 309. 



30 GENERAL PSYCHOLOGY 

habit-interference) has been reported particularly by Yerkes, 
Hunter, and Wylie. The second investigator mentioned has 
shown that the formation of a given habit interferes greatly with 
the formation of an opposite habit, while the formation of this 
second habit may not affect the retention of the former. Cases 
are also on record where transfer has occurred between visual 
and auditory habits, as opposed to transfer between two habits 
each aroused by vision or hearing. Other studies of habit- 
formation might be cited, but the foregoing will give a clear 
idea of the methods employed and the goals to be attained. 

Imitation. — In the topic of "Imitation" and the following 
one of "Delayed Reaction" we shall describe briefly two im- 
portant examples of "higher capacities" in animals as referred 
to above, page 14. We shall define imitation here in the simplest 
possible manner as the performance of an act by animal No. 1 
by virtue of having perceived the same act performed by 
animal No. 2. We shall discuss imitation at greater length 
in the chapter on "Social and Racial Psychology," page 91. 
At the present point our intention is to illustrate the typical 
method of studying the problem experimentally whether in 
man or animals. 

Haggerty has made the most thorough test of the presence 
and nature of imitation in animals, using monkeys as subjects. 
Studies on imitation have also been made by Hobhouse, Thorn- 
dike, Berry, and Watson. Haggerty's method was as follows: 
Monkey No. 1 was placed in a cage where he could secure food 
by climbing up the wire, jumping to a chute, reaching his hand 
up this, and pulling a string. If monkey No. 1 failed to learn 
the problem, he was taught it by the experimenter. Monkey 
No. 2 was now tested and, let us assume, failed. No. 2 is now 
confined in a small cage within the larger one and in such a 
position that he can see monkey No. 1 solve the problem and 
get the food. If after witnessing this performance a certain 
number of times No. 2 is given a chance and succeeds (even 



ANIMAL PSYCHOLOGY 31 

after much effort), it is evident that No. i's behavior has aided 
him. Does this result mean that imitation is present? No, 
not if by imitation it is meant that animal No. 1 concludes 
because No. 2 secured food in such and such a manner that 
therefore he, No. 1, can also. It does indicate that his atten- 
tion has been vividly caught and held by seeing another member 
of his own species secure food, and that when he himself was 
given an opportunity he went to the place where food had 
appeared the time before. The influence excited by the first 
monkey upon the second one was a social influence, a specific 
incentive to increased activity. There is no clear evidence 
that animals imitate rationally in the sense that man sometimes 
does. However, the facts are not entirely clear with respect 
to what man does in cases of imitation. 

The Delayed Reaction. — The instances of animal behavior 
so far described are all cases of responses to present stimuli. A 
color, a sound, or a series of pathways is presented to the animal, 
and he is forced to make a selection. Upon the basis of his 
ability to select we determine the stimuli to which he is sensi- 
tive. The delayed reaction is a study of responses made when 
the stimuli are absent at the moment of response. A cat, for 
example, sees a mouse appear at a hole. The mouse disappears, 
and sooner or later the cat reaches the hole. The delayed 
reaction introduces, in addition to this element of delay between 
the disappearance of the stimulus and the beginning of the 
response, the element of selection. Let us suppose that there 
are three holes and that the mouse had appeared in each one 
an equal number of times. After the mouse has appeared and 
disappeared at one hole, would the cat pick out which hole to go 
to? If it could for a short interval of time, how much would this 
need to be increased before the limit of the cat's ability would 
be reached? And then, most important of all, what method did 
the animal use in solving the problem? The delayed reaction 
has been studied with rats, dogs, cats, raccoons, and children. 



32 



GENERAL PSYCHOLOGY 



In Fig. 9 is shown the apparatus used with cats. It is in 
principle the same as the apparatus used in the problem with 
other animals. The method of procedure is as follows: an 
animal is placed in R, the release box; a light can be turned 
on in either of three boxes; the animal's exit from the apparatus 
is blocked save through the lighted box. When the animal is 




■■■:■."■ /:/ : ■ ■'. ' 



Fig. 9. — The delayed-reaction box (after Yarbrough). R is the release 
box in which the animal is detained during the interval of delay. An 
electric-light bulb is visible in the central box at the rear. The animal must 
escape from the apparatus through the exit E of one of these three boxes, 
each of which can be illuminated at will. The experimenter stands near R, 
separated from the apparatus by an opaque screen. This prevents the 
animal from catching cues or suggestions from him. 



released it must learn always to go through the box which is 
lighted (or in which a noise is sounded, if sound is the stimulus) 
and return to R, where food is given. When once the animal 
has perfected this association of light and food, the real problem 
begins. The experimenter then places the animal in the 
release box; turns on the light in some one of the three boxes; 
when the animal has seen the light, turns it off; keeps the animal 
in the release box for a certain interval of time; and finally 



ANIMAL PSYCHOLOGY 33 

releases it. Will it go out the box that was most recently lighted? 
If this is the case, the period of delay is increased, until the limit 
of the animal's ability is reached. The maximal intervals of 
successful delay obtained in this problem are as follows: 

Rats 1 to 5 seconds 

Dogs 1 to 3 minutes 

Raccoons 10 to 25 seconds 

Cats * 16 to 18 seconds 

Child 1 \ yrs 20 seconds 

Child 2\ yrs 50 seconds 

Child 5 yrs At least 20 minutes 

More interesting than the length of time that an animal can 
successfully delay are the methods employed by it. (It must 
be remembered that there is nothing outside the animal's body 
to tell him which box to pass through.) The rats, cats, and 
dogs (Hunter and Yarbrough) had to keep their heads or bodies 
oriented toward the proper box if the correct reaction was to 
occur. Raccoons, dogs (according to Walton), and children, 
however, could lose their orientations during the delay and still 
react correctly. There was some process within their bodies 
which could be used to guide the proper response although the 
animals had not remained facing the proper box during the 
interval of delay. The hypothesis advanced in explanation is 
that this process or cue comes from the muscles of the animal 
and is kinaesthetic in kind. Its function is that of an idea, 
because it enables the animal to react to an absent object in a 
selective manner, although it — the cue — has not been continu- 
ously present. 

Conclusion. — -We have now canvassed typical problems and 
results from the field of animal psychology. We have seen 
enough of the methods to gain a fair insight into the methods 
of procedure and the safeguards that are employed. There 
are numerous problems, however, such as that of language 



34 GENERAL PSYCHOLOGY 

capacities, that we have been unable to describe for lack of 
space, although they are of great importance in a comprehen- 
sive survey of the field. Our introductory discussion of this 
field leads us to see the importance of careful, objective methods 
in a phase of psychology that is very concrete. It calls our 
attention to forms of behavior that are common to man and 
animals and also to forms that are strikingly different. The 
variations in the sensory and motor equipment of man and 
animals are the things that are termed variations in intelligence. 
An animal that can see more or hear more than another animal 
is to that extent the more intelligent of the two. So the animal 
that can adjust itself by muscular movements in the most 
varied ways is the most intelligent animal in that respect. This 
latter difference may occur between animals possessing the 
same sense-organs and the same muscles. The difference is 
one that is determined within their nervous systems, for some 
nervous systems are inherently less plastic and adjustable than 
others. In the following chapter on "Individual Psychology" 
we shall deal continually with questions concerning this general 
intelligence or adjustability in the human organism. 

REFERENCES 

Carr, H. A., and Watson, John B. "Orientation in the White Rat," 

Jour. Comp. Neur. and Psych., XVIII (1908), 27-44. 
Haggerty, M. E. "Imitation in Monkeys," Jour. Comp. Neur. and 

Psych., XIX (1909), 337-455- 
Hunter, W. S. "Delayed Reaction in Animals and Children," 

Behav. Mon., II (1913), No. 6. 
. "The Auditory Sensitivity of the White Rat," Jour. Animal 

Behav., IV (1914), 215-22; V (1915), 3i~2-29. 
Jennings, H. S. The Behavior of Lower Organisms. New York: 

1906. 
Johnson, H. M. "Audition and Habit Formation in the Dog," Behav. 

Mon., II (1913), No. 8, 



ANIMAL PSYCHOLOGY 35 

Lashley, K. S. "The Color Vision of Birds. I. The Spectrum of 

the Domestic Fowl," Jour. Animal Behav., VI (1916), 1-26. 
Thorndike, E. L. Animal Intelligence. New York: 1911. 
Ulrich, J. L. "Distribution of Effort in Learning in the White Rat," 

Behav. Mon., II (191 5), No. 10. 
Washburn, M. F. The Animal Mind. Second edition. New 

York: 191 7. 
Watson, John B. Behavior. New York: 1914. 
Yerkes, R. M. "The Sense of Hearing in Frogs," Jour. Comp. New. 

and Psych., XV (1905), 279-304. 
Yoakum, C. S. "Some Experiments on the Behavior of Squirrels," 

Jour. Comp. Neur. and Psych., XXIX (1909), 541-68. 



CHAPTER II 
INDIVIDUAL AND APPLIED PSYCHOLOGY 

I. INDIVIDUAL PSYCHOLOGY 

Introduction. — One of the most striking characteristics of 
human nature is the fact of individual variation. This variation 
occurs not only in the sort of material that goes to make up the 
consciousness of the person, but also very significantly in the 
ability to use this consciousness in solving the problem of 
adjustment to environmental demands. Individuals vary in 
temperament and mood, their emotional responses differing 
in the same situations. Their sense-organs vary in acuity, so 
that what one can see or hear may be quite beyond the range of 
another. In addition variation may be due to defects in the 
sense-organs. To illustrate, the person may be blind to all 
colors or only to certain ones; he may be deaf to certain tones; 
or he may be unable to feel contact over certain areas of his 
skin (and thus be anaesthetic) . In a similar manner variations 
can be recounted in each of the specific types of conscious 
processes. Many of these will be discussed in Part II, where 
an analysis is made of normal adult consciousness. At that 
time a brief description will be given of one of the most note- 
worthy of individual differences in conscious content, viz., 
variations in image-type. It is sufficient to say here that in 
thinking of an object when the object itself is absent some 
individuals make use of visual images (mental pictures) ; others 
think in terms of how the object sounds (auditory imagery); 
others in terms of how it feels to contract the vocal muscles 
and speak the name of the object (vocal-motor imagery), etc. 
A very nice problem exists in the diagnosis of the type of imagery 
used by a given individual. 

36 



INDIVIDUAL AND APPLIED PSYCHOLOGY 37 

We have been giving samples of the problems of individual 
variation in conscious content. Of greater importance, how- 
ever, at the present time are the problems arising from behavior. 
There are, of course, functions worthy of analysis related to 
each of the states of consciousness whose variations have just 
been mentioned. The most significant behavior problems in 
individual psychology, however, are those which deal with 
ability to solve typical difficulties in the environment. No 
one problem can be chosen in whose solution all persons will 
prove equally efficient, for they will distribute themselves 
through all the grades from very poor to excellent. The dis- 
covery and quantitative measurement of these variations in 
ability are of great practical importance in two fundamental 
directions. In the first place, it is important to know how an 
individual ranks with the other members of his group in general 
ability, i.e., in his native capacity to learn, in his ability to 
adjust himself to new situations. Those who occupy the 
lowest level of ability are known as the feeble-minded. Genius 
is at the other extreme, occupying the highest level of adaptive 
ability. In the second place, there are studies of special ability. 
These center attention primarily upon an individual's relative 
capacity in a particular situation, forming the basis of scientific 
vocational guidance, a field of study which is as yet in its infancy. 
It involves the perfection of tests for the selection of those best 
qualified for musicians, telegraphers, salesmen, officers in the 
army and navy, aviators, gunners, etc. Inasmuch as the 
various rankings of individuals are determined by the results 
of tests, individual psychology includes within itself the field 
popularly and technically known as that of "mental tests." 
In so far as the tests concern the variations of general ability 
with age, they include the most scientific and valuable portion 
of child and adolescent psychology. 

The Binet-Simon Scale. — The best-known and most widely 
used scale of mental tests for general ability is the Binet-Simon 



38 GENERAL PSYCHOLOGY 

scale, first published in 1905. This was devised by the French 
psychologist Alfred Binet in 1904 in response to the request that 
he survey the schools of Paris for the purpose of detecting feeble- 
minded pupils. The scale as constructed was largely an elabora- 
tion and compilation of tests that Binet and his collaborator 
Th. Simon had already used for another purpose. The essential 
characteristics of the scale are as follows: (1) The establishment 
of the mental age of a child is sought in terms of the average 
performance of other children of that age. (2) A group of 
five tests is provided for each age, except at year 4. (3) The 
ages provided for range from one to fifteen. In addition five 
tests for adults are given. (4) All of the tests after the first 
two years require the understanding of language, and most of 
them require the subject to reply in terms of language. (5) Only 
one individual is examined at a time, the time required being 
from thirty minutes to an hour. A bare outline of the tests 
used from three years on is as follows : l 

THREE YEARS 

Shows nose, eyes, and mouth. 

Repeats 2 digits. 

Enumerates objects in a picture. 

Gives family name. 

Repeats a sentence of 6 syllables. 

FOUR YEARS 

Gives own sex. 

Names key, knife, and penny. 
Repeats 3 digits. 
Compares 2 lines. 

FIVE YEARS 

Compares 2 weights. 
Copies a square. 

1 A. Binet and Th. Simon. A Method of Measuring the Development 
of the Intelligence of Young Children. Trans, by Town (Chicago: 1913), 
pp. 7-9. 



INDIVIDUAL AND APPLIED PSYCHOLOGY 39 

Repeats a sentence of 10 syllables. 

Counts 4 pennies. 

Plays game of patience with 2 pieces. 

six YEARS 

Distinguishes between morning and afternoon. 

Defines in terms of use. 

Copies a lozenge. 

Counts 13 pennies. 

Compares faces from the aesthetic point of view. 

SEVEN YEARS 

Right hand; left ear. 

Describes a picture. 

Executes 3 commissions. 

Gives value of 9 sous, 3 of which are double. 

Names 4 colors. 

EIGHT YEARS 

Compares 2 remembered objects. 
Counts from 20 to o. 
Indicates omissions in pictures. 
Gives day and date. 
Repeats 5 digits. 

NINE YEARS 

Gives change from 20 sous. 
Defines in terms superior to use. 
Recognizes all the pieces of our money. 
Enumerates the months. 
Understands easy questions. 

TEN YEARS 

Arranges 5 weights. 
Copies drawings from memory. 
Criticizes absurd statements. 
Understands difficult questions. 
Uses 3 given words in 2 sentences. 



40 GENERAL PSYCHOLOGY 

TWELVE YEARS 

Resists suggestion (length of lines). 

Composes one sentence containing 3 given words. 

Says more than 60 words in 3 minutes. 

Defines abstract terms. 

Discovers the sense of a sentence the words of which are mixed. 

FIFTEEN YEARS 

Repeats 7 digits. 

Gives 3 rhymes. 

Repeats a sentence of 26 syllables. 

Interprets a picture. 

Solves a problem from several facts. 

ADULT 

Solves the paper-cutting test. 

Rearranges a triangle. 

Gives differences in meaning of abstract terms. 

Solves the question of the President. 

Gives a resume of the thought of Hervieu. 

The calculation of the mental age of an individual on the 
basis of the tests outlined above is not a simple matter. The 
results secured are never so clear-cut as to make the determina- 
tion automatic, for a child will pass all of the tests for a certain 
age and a scattered number of tests for higher ages. Accord- 
ingly, in giving him his final ranking, one proceeds as follows: 
the age at which the child passes all tests is termed his base 
age; then for every additional five tests belonging to higher 
ages he is credited with one year in addition to his base age. 
A child is diagnosed as retarded if his mental age is one or two 
years below his chronological age. 

Criticisms of the Binet-Simon Scale. — The Binet scale 
established itself almost at once as the most reliable method of 
gauging general ability then in existence. Yet its use suggested 
many defects which led Binet himself to revise it. In this 



INDIVIDUAL AND APPLIED PSYCHOLOGY 41 

country revisions have been proposed, particularly by Kuhl- 
mann, Goddard, Terman, and Yerkes. Of these the latter two 
have made the most significant changes. In general we may list 
the chief criticisms of the scale as follows: (1) The tests for the 
early ages are too easy, and those for the upper ages are too 
difficult. Various other tests seem misplaced as to age. (2) The 
directions given for the application and grading of the tests are 
so general that confusion arises among different investigators. 
(3) The scale utilizes language ability to such an extent that 
it is inapplicable, particularly to speech defectives and to the 
deaf. Investigators have also found difficulty in adapting the 
scale to non-English-speaking subjects. (4) The method of 
determining mental age is inadequate. The Terman, or Stan- 
ford, revision attempts particularly to remedy the first and sec- 
ond criticisms. It also meets the fourth by following the 
German psychologist Stern's method of calculating mental age. 
In addition a more extended series of thoroughly tested and 
standardized tests for adults is offered. The Yerkes revision 
places chief emphasis upon criticisms 2 and 4. Criticism 3 
cannot be met by a remodeling of the Binet scale, but a series 
of non-language tests must be devised and standardized. This 
task has been done most extensively by Pintner and Paterson 
(191 7), and later by the army psychologists. 

Performance Tests. — Let us first consider the scale of per- 
formance tests recommended by Pintner and Paterson, who were 
stimulated in their work by the necessity for testing deaf chil- 
dren. The scale includes fifteen tests derived from various 
sources. Three of these tests we shall describe briefly. (1) The 
Seguin-Goddard form board (Fig. 10) has been extensively used 
by Sylvester upon children of various ages. The problem for 
the child is the laying of each block in its proper place in a 
minimal time with no errors. The time limit allowed for solu- 
tion is five minutes. (2) The pictorial-completion test devised * 
by Healy (Fig. n) requires the child to complete the picture 



42 



GENERAL PSYCHOLOGY 



by the proper insertions of the cut-out portions. (3) The Knox 
cube test uses five small cubes. Four of these are placed in a 
row before the child and the fifth is held by the experimenter, 
who then calls the child's attention to his movements and taps 
the cubes with the one he holds. The number and the order of 
the taps may vary as follows: 1-2-3-4, 1-2-3-4-3, 1-3-2-4-3, 
etc. At the conclusion of one number the tapping cube is 






Fig. 10. — A typical form board 



placed before the child, and he is told to tap likewise. A definite, 
invariable series of numbers is used with all subjects tested. 

Pintner and Paterson, on the basis of extensive tests made 
by themselves and other research students, offer tables showing 
the grades made at various ages. It is found that both the 
time consumed and the errors made in the test decrease with 
the increasing age of the subject tested. In applying the scale 
to an individual child, the question of age credit comes up at 



INDIVIDUAL AND APPLIED PSYCHOLOGY 



43 



once. For example, what score must a child make on a given 
test in order to pass as a six-year-old in that test? Credit is 
not given unless the child's record is as good as the lowest of the 
upper 75 per cent of the children tested at that age. Seven-year 




Fig. ii. — Healy's pictorial completion test 



44 GENERAL PSYCHOLOGY 

credit is given if the grade secured falls in a class with the 
upper 75 per cent of the children who are seven years old. In 
determining finally the mental age of a child the procedure may 
be the same as in the Binet scale: that is, a basal age is deter- 
mined at which the child passes all tests; then additional 
credit is given for higher tests that may be passed. The mental 
age is the sum of the two. 

The Calculation of Mental Age. — Terman and Yerkes have 
been the chief critics of the Binet-Simon method of determining 
mental age, which we have already presented in connection with 
the original scale and with the performance scale. Terman, 
following Stern, suggests the use of an intelligence quotient. It 
combines two points made by Binet into a single expression: 
that is, in place of stating a mental age (which Terman cal- 
culates on Binet's principle) and then stating its relation to the 
chronological age, Terman divides the former by the latter and 
terms the result the intelligence quotient or the IQ. This method 
recognizes the fact that a retardation of one, two, or three years 
in an eight-year-old child is more serious than the same retarda- 
tion in a twelve-year-old one. A child of eight years and with 
a mental age of eight has an IQ of ioo. If the mental age is 
10, thelQ for the same child is 125. There is a probability that, 
barring accident and disease, the IQ remains the same for each 
individual throughout his lifetime. Terman's work was carried 
out upon 1,000 unselected children, and therefore well repre- 
sents the frequencies with which the various IQ's occur in the 
general population from which they were taken. He found 
that only 1 per cent equal or exceed a score of 130; that 4 per 
cent come between 130 and 122; that one- third equal or exceed 
106; that one- third equal or go below 95; and that 1 per cent 
equal or go below 70. As a result of his experiments Terman 
classifies the grades of intelligence as follows: 1 

1 L. M. Terman. The Measurement of Intelligence (Boston: 1916), 
p. 79. 



INDIVIDUAL AND APPLIED PSYCHOLOGY 45 

IQ Classification 

Above 140 "Near" genius or genius. 

120-140 Very superior intelligence. 

1 10-120. Superior intelligence. 

90-110 Normal, or average, intelligence. 

80- 90 Dulness, rarely classifiable as feeble- 
mindedness. 

70- 80 Border-line deficiency, sometimes 

classifiable as dulness, often as 
f eeble-mindedness . 
Below 70 Definite f eeble-mindedness. 

In the following section the nature of feeble-mindedness 
will be discussed and illustrated. Here, in contrast, we shall 
cite one of Terman's cases of very superior intelligence. Notice 
should be given to the way in which the child's record bears 
out the IQ. 

T. F. Boy, age 10-6: mental age 14; IQ 133. At 13-6 tested 
at "superior adult," and had vocabulary of 13,000 (also "superior 
adult"). Son of a college professor. Did not go to school till age 
of 9 years and was not taught to read till 8^. At this writing he 
is 1 5! years old and is a senior in high school. He will complete the 
high-school course in three and one-half years with A to B marks, 
mostly A. Gets his hardest mathematics lessons in five to ten 
minutes. Science is his play. When he discovered Hodge's Nature 
Study and Life at age of 11 years, he literally slept with the book till 
he almost knew it by heart. Since age 12 he has given much time 
to magazines on mechanics and electricity. At 13 he installed a 
wireless apparatus without other aid than his electrical magazines. 
He has, for a boy of his age, a rather remarkable understanding of 
the principles underlying electrical applications. He is known by 
his playmates as "the boy with a hobby." Stamp collections, butter- 
fly and moth collections (over 70 different varieties), seashore collec- 
tions, and wireless apparatus all show that the appellation is fully 
merited. He chooses his hobbies and "rides" them entirely on his 
own initiative. 1 

1 Ibid., p. 99. 



46 GENERAL PSYCHOLOGY 

Yerkes, in his criticism of the Binet method of calculating 
mental age, suggests a point scale where the child's standing is 
given in terms of points and not in terms of years. A perfect 
score on the twenty tests (borrowed largely from those of Bihet- 
Simon) of his scale is ioo. One characteristic of merit in this 
new system is the fact that in many tests partial credit is given 
for partial performance in a way not possible with the Binet 
system of grading. Data have been gathered with the point 
scale showing approximate normal scores for children of various 
ages. By comparison with these standards (which are always 
open to further extension and revision), it is possible to deter- 
mine the rank of a given child relative to the average or normal 
score for his age. The individual score divided by the normal 
for that age gives the coefficient of mental ability. 

Group-Examination Methods. — The Binet-Simon scale and 
its modifications are essentially adapted to the testing of one 
individual at a time. Because of the length of time involved, 
they are not therefore suited to the examination of large groups 
of individuals, and yet this is practically necessary if one is to 
obtain a view of the intelligence of whole communities. Within 
recent years tests have^been devised which can be given to 
groups of several hundred people at the same time. Each indi- 
vidual is supplied with an examination test blank and the group 
is given a definite time-interval of one minute, five minutes, etc., 
during which to work on each test. The score is indicated 
by the relative amount of work accurately completed in the 
time allowed. By this means one can rapidly survey a school 
system, a community, or an organization and secure its relative 
intelligence-rating. The practical importance of such data is 
tremendous in its possibilities. Why are certain city neighbor- 
hoods less progressive than others? Why are certain sections 
of the country poorly developed? The answer may well be 
found, not in the physical advantages or disadvantages of the 
land, but in the mental caliber of the population. 



INDIVIDUAL AND APPLIED PSYCHOLOGY 47 

The Feeble-minded. — -The scales for the measurement of an 
individual's relative mental ability are of fundamental psycho- 
logical and sociological importance. We have just seen a sug- 
gestion of this in the account of group methods of examination. 
The group method is opening up a tremendous field where the 
chief interest is in the relative ability of all persons in the popula- 
tion. The individual method of Binet is chiefly interested in 
those of very inferior intelligence, the feeble-minded. The 
average and superior individuals may be held back by adverse 
social conditions, but they will never clog the machinery of 
progress with inefficiency, subnormal offspring, and crime. 
This is largely accomplished by the feeble-minded. As a 
result of the appreciation of this fact, the diagnosis of 
the mental status of the inmates of public institutions and 
of juvenile offenders is now an accepted and widespread 
procedure. 

Estimates of the frequency of feeble-mindedness among 
delinquents range from 25 per cent to 50 per cent. One cannot 
return a simple answer to the query concerning the constitution 
of the criminal mind. It is certain, however, that a great por- 
tion of these individuals become criminals because of inability 
to understand and appreciate the customs and ideals of their 
group. Such an inability to understand is an intellectual 
deficiency. The frequency of feeble-mindedness is not so great 
among the general population. Terman found, as indicated 
above, 1 per cent feeble-minded in the 1,000 unselected school 
children studied. The percentage in the general population, 
however, is probably higher because the school systems include 
only the higher grades of the feeble-minded and the doubtful 
or borderline cases. 

Three main grades of feeble-mindedness are recognized: the 
idiot, the imbecile, and the moron. The characteristic descrip- 
tions usually given of their industrial capacities after complete 
development has occurred are as follows: 



48 GENERAL PSYCHOLOGY 



MENTAL AGE 


CAPACITY FOR ADJUSTMENT 


GRADE OF DEFECT 


Less than i yr. 


Helpless 


Low idiot 


i yr. 


Feeds self, eats everything 


Middle idiot 


2 yrs. 


Eats discriminatingly 


High idiot 


3 yrs. 


No work, plays little 


Low imbecile 


4 yrs. 


Tries to help 


Middle imbecile 


5 yrs. 


Only the simplest tasks 


Middle imbecile 


6 yrs. 


Tasks of short duration, 






washes dishes 


Middle imbecile 


7 yrs. 


Little errands in the house 


High imbecile 


8 yrs. 


Errands, light work, makes 






beds 


Low moron 


9 yrs. 


Heavier work, scrubs, 






mends 


Middle moron 


io yrs. 


Good institution helpers; 






routine work 


Middle moron 


ii yrs. 


Fairly complicated work 
with only occasional 






oversight 


Middle moron 


12 yrs. 


Uses machinery ; cares for 
animals; no supervision; 






cannot plan 


High moron 



These conditions just tabulated are generally regarded as 
incurable. Goddard has shown in the Training School at Vine- 
land, N.J., that feeble-minded children who have reached their 
complete development fail to improve when tested with the 
same scale year after year. The accompanying figure (Fig. 12) 
shows three types of feeble-mindedness, all of which come from 
seriously defective ancestry. Although we cannot give a 
description of each case here, we shall comment briefly on that 
of Will T. His father was alcoholic and a sex offender. His 
mother, three of her brothers, two of her sisters, and her parents 
were feeble-minded. His two brothers and four half-brothers 
were also subnormal. These facts point to the most serious 
question in relation to feeble-mindedness, viz., the propagation 




Fig. 12. — Three feeble-minded types (after Goddard) 

Will T. (upper), age 21, mental age 8. 
Isaac Q., age 16, mental age 10. 
Prudence Q., age 17, mental age 3. 



50 GENERAL PSYCHOLOGY 

of defective children (always in large numbers) who become a 
social burden if not a social menace. The detection of these cases 
is one of the most important practical tasks of psychologists. 

The Inheritance of General Intelligence. — The tale of the 
inheritance of a low grade of general intelligence is ominous, 
and is only offset by the reflection that normal and high-grade 
ability must follow the same hereditary law. The fact, 
furthermore, that feeble-mindedness is recessive (Goddard) 
makes it less frequent in appearance in the general population. 
Goddard has published the most extensive studies of the 
inheritance of mental defect. The most striking case, and 
therefore the one most widely known, is that of the Kallikak 
family. The story is as follows: During the American Revolu- 
tion, Martin Kallikak, a young man of good family, became the 
father of an illegitimate son. The child's mother was a feeble- 
minded girl and the boy, Martin Jr., was like her. From this 
boy have come 480 descendants, practically all of whom have 
been feeble-minded and criminalistic. One of the last of these 
is Deborah, a moron, in the Vineland Training School. The 
story has another side, however. After the Revolution Martin 
married a normal girl, and from that union have come none but 
normal descendants, many of whom are of excellent ability. 
The two branches of the family live in the same section of the 
state, although they are in ignorance of their relationship. 
Indeed in one instance a member of the abnormal line is in the 
employ of a descendant in the other line. Nothing could show 
more clearly than these two lines of descent the terrible heredi- 
tary importance of mental defect. 

The reader should study carefully the accompanying chart, 
on which are presented a few of the details of this family. Of 
the 480 descendants of Martin, 143 were conclusively proved 
to be feeble-minded, 36 were illegitimate, 41 were sexually 
immoral, 3 were criminals, 3 were epileptics, 24 were confirmed 
alcoholics, and 82 died in infancy. These individuals have in 



INDIVIDUAL AND APPLIED PSYCHOLOGY 



5i 



general married, and their 
mates were usually others 
of similar ability; accord- 
ingly, Goddard finally had 
on his charts 1,146 individ- 
uals. Fig. 13 traces De- 
borah's ancestry in detail 
as far back as her grand- 
parents. No greater argu- 
ment for a prompt and 
serious consideration of 
eugenics could be offered 
than these records of the 
inheritance of low mental- 
ity with its resulting crime, 
poverty, and disease. 

The Use of Statistical 
Methods. — The discussion 
must now turn from results 
back to methods. Individ- 
ual psychology has made 
a more extensive and sig- 
nificant use of statistical 
method than any other 
field of the science. This 
condition has grown out 
of the dominating position 
occupied in the field by the 
mental tests which we have 
described above. These 
tests, as our exposition has 
already brought out, aim 
at placing a given individ- 
ual in his relative place in 







(U o 
<U O 

en <u 



a 
: = 

o 

X 



a 

<u 

a. 
a 

to 



<4J — 



ci >> 



u 



»-" .3 



T3 



>. 



XI 



T3 

a 



,a 

>-< 
O 

<D 

ft 



J? ft* 



h 



52 GENERAL PSYCHOLOGY 

the population according to his ability in specific capacities 
and general adjustments. In order to do this it is necessary 
first to establish normal, or mean, records for the population 
concerned. The next step involves determining whether or 
not the norm is probably the true one for the group examined. 
There will be a certain amount of variation in the values 
secured for each mean when different classes of people or 
different conditions come into the experiment. It then 
becomes important to determine whether or not these dif- 
ferences are significant. Suppose, for example, that A has 
made a large series of tests on children five years old, and has 
found that the average, or mean, score is 10 points. He 
now tests another group of children of the same age and 
secures a mean of 12 points. Is this an accidental and insig- 
nificant difference in results, or does it indicate the presence of 
disturbing factors in the experiment? Mathematical formulas 
have been worked out by means of which this question can be 
settled. The same question must be asked when tests are made 
at different ages in pursuit of "age differences." Let us assume 
that there is a difference in the average scores for a group of 
children five years old and a group who are six. Is this a sig- 
nificant and therefore an "age" difference, or is it insignificant? 
Again, the above-mentioned formulas are used to measure the 
probable error of the difference of the two means. Unless the 
numerical difference exceeds the probable error at least four 
and a half times, the difference can hardly be held as significant. 
The illustration that we have used concerns the effect of age on 
the average score for a certain test. In like manner one must 
deal with the effects of any one of many other possible factors 
that may affect the results. 

In addition to these data it is often very important to know 
how an individual's ranking in one test compares with his posi- 
tion in another. Is a tall person also in general a heavy one? 
Is one who ranks high in mathematics also of excellent ability 



INDIVIDUAL AND APPLIED PSYCHOLOGY 53 

in science? To the extent that abilities, tendencies, or processes 
vary directly one with another, to that extent do we credit 
them with a causal relationship. This is positive correlation. 
Negative cases of correlation are those that vary inversely. 
Mathematical ability may always be great in those of poor 
literary ability, and vice versa. In this case one would speak 
of antagonistic causes at work. Instances of indifferent correla- 
tion are those where excellence in one field may or may not be 
accompanied by ability in another field. The relationship is 
one of chance. It is possible with problems of correlation to 
use mathematical formulas for determining the exact facts, and 
in many cases this determination is absolutely necessary if 
obscure relationships are to be detected. The method of cor- 
relation has the further value of aiding in the determination 
of exactly what is meant by such terms as general intelligence. 
Thus, if one test or scale, x, is known to correlate highly with 
intelligence, as the term is popularly understood, other tests 
or scales which correlate highly with x will also correlate highly 
with intelligence. And so one can gradually discover the ways 
in which intelligence acts. In standardizing tests, correlation 
is furthermore of particular value in checking up the test with 
the practical situation. Do the men who stand high or low 
in the tests also rank correspondingly in their duties as police- 
men, as salesmen, as students, etc.? The answer to this ques- 
tion is the final criterion of a test's (or of a scale of tests') specific 
validity. 

II. APPLIED PSYCHOLOGY 

It is difficult to draw distinctions between applied psy- 
chology and any of the other fields included in the present book. 
The term makes an unwarranted division between the psy- 
chology of an individual and the applications of this knowledge 
to some practical end. An adequate understanding of human 
nature involves the acceptance and use of both points of view. 



54 GENERAL PSYCHOLOGY 

When we approach the study of the abnormal, the social, the 
animal, etc., we apply- all the psychology that is at our com- 
mand in reaching an understanding of the problem. Likewise 
in the analysis of the normal adult individual — the task of 
"pure" psychology — one applies all of the information avail- 
able in order to solve that question. Inasmuch, however, as 
the term "applied psychology" is in general use, we may employ 
it to cover certain comments upon psychology in medicine, law, 
education, and business. 

Psychology in Its Relation to Medicine and Law. — Psy- 
chology and medicine come closest together in the topics we 
shall discuss in the following chapter on "Abnormal Psy- 
chology." The physician will be helped, to be sure, by a 
general understanding of the basic facts of human nature. His 
chief help, however, will come in the treatment of nervous and 
mental diseases from an understanding and appreciation of the 
following two points: 

i. He should be familiar with the methods used by psy- 
chologists in testing the various sense-organs. This is no simple 
matter. It is a field for specialization in itself, for there are 
specific precautions to be taken in the study of color-blindness, 
in the diagnosis of defects in touch, etc. The chief interest in 
this topic finally centers upon the study of injuries to the 
nervous system with their accompanying mental defects. 
Medical men themselves have made the chief contributions 
to these investigations, but it is perhaps safe to say that it is 
only when the data and methods are put in relation to those of 
psychology as a whole that their full significance is caught. 

2. The second chief value of psychology and medicine to 
each other lies in the analysis of the hidden forces of human 
character. Sigmund Freud has studied in great detail the bits 
of experience that become forgotten or voluntarily and even 
anxiously cast aside by each individual. These the average 
student has regarded as of no further influence upon conduct. 



INDIVIDUAL AND APPLIED PSYCHOLOGY 55 

Freud, however, has claimed, and has presented much evidence 
to show, that these "repressed complexes" do persist in the 
unconscious. From time to time in certain individuals they 
reappear and distort consciousness, and in this way they produce 
the characteristic symptoms of many mental diseases. In a 
less serious form they crop out in the dreams, wit, lapses of 
speech, etc., of the "normal" individual. We shall discuss this 
fascinating topic briefly in the next chapter, and at that time 
the present comments should be recalled. It may well be 
insisted here, however, as it was above, that this field lacks 
breadth and sane perspective when it cuts free from the data 
on human nature presented in general psychology. 

The contributions of psychology to law are much more 
one-sided. To understand law in its broad significance, one 
must appreciate the nature of society and of those forces which 
govern the interaction of men. Much of this material can be 
secured only in social psychology, which we are to review briefly 
in chapter iv. Mention may be made of two ways in which 
scientific data have been applied to the problems of the courts. 

1. An effort has been made to secure criteria of valid testi- 
mony, and to measure the variations in testimony under different 
conditions. Subjects are shown pictures or events, e.g., for a 
brief interval of time and are then requested to give a report 
of what they have seen. Many mental processes are involved: 
concentrated attention, discrimination, power of interpreta- 
tion, immediate memory, ability to adjust one's self quickly, etc. 
Even where the results do no more than confirm what one's 
experience would lead him to expect, they are illuminating in 
pointing out the complexity of the testimony situation. It is 
found particularly that children and abnormal adults do not 
testify accurately; that accuracy and quantity of testimony are 
to some extent in inverse ratio; that the form of the interroga- 
tion used in cross-examination has a great effect upon the evi- 
dence given; and that what a witness perceives depends 



56 GENERAL PSYCHOLOGY 

markedly upon his attitude and expectation. Further com- 
ments will be made in Part II, chapter i, in the account of 
attention. 

2. At the present time the most valuable aid that psychology 
can offer law is in the diagnosis of the general intelligence of 
offenders. Although it is of supreme importance, we need not 
dwell upon this topic. The foregoing discussion of individual 
psychology has presented the methods of diagnosis used and 
the hereditary evils necessary to be combated. Various courts 
and institutions have already seen the necessity of arriving at 
an understanding of their wards before assessing punishment 
or planning reform. 

The Relation of Psychology to Education. — The process of 
educating an individual is the process of adjusting him to his 
environmental problems. One may thus term the whole of 
the science of psychology "educational psychology." The care- 
ful student of education should be intimately familiar with the 
topic of instincts because they are the fundamentals upon which 
all modifications by experience must rest. He should be thor- 
oughly acquainted furthermore with the psychology, or facts, 
of learning and memory in general. Finally, in particular there 
should be a sympathetic understanding of the field of general- 
and special-ability tests. Much of the valuable material in 
these topics owes its discovery to the urgency of pedagogical 
demand and to the enthusiasm of students of education. These 
problems are certain portions of the general field of human 
nature which, without the aid of men primarily interested in 
educational problems, would have been developed neither as 
rapidly nor as soon as they have been. Educational psychology, 
however, as a special field, deals with human nature so far as 
schoolroom conditions may make it peculiar or so far as unique 
adjustments may there be required of it. The principles of 
learning and habit-formation in general, e.g., are topics for 
inclusion in this field only so far as school children learn under 



INDIVIDUAL AND APPLIED PSYCHOLOGY 57 

peculiar conditions. Typical important problems are these: 
What is the proper length of the recitation period? What 
learning processes are peculiarly involved in arithmetic, in 
spelling, in geography, etc.? How shall one grade or estimate 
ability in the various lines of training? What are the factors 
determining an individual's progress in the curriculum? To 
what extent are entrance examinations indicative of the fucure 
relative ranking of individuals? To what extent can one's 
ability in higher grades be predicted from his rank in lower 
grades? These and a host of other similar problems are being 
attacked and solved. The field of mental tests has an exten- 
sion here in the scales devised for the grading of special school 
abilities such as arithmetic, writing, and language. Yeoman 
work has also been done in making intensive studies of the 
mechanics of reading and writing — -two habits of fundamental 
importance in the educational scheme. Instruction and train- 
ing in these professional problems are supplanting the earlier 
work, the attitude of which was that educational psychology 
consisted in general psychology plus a few more or less obvious 
applications to schoolroom conditions. 

Psychology and Business. — -The study and analysis of 
business problems from the psychological standpoint are increas- 
ing rapidly. The interest and the confidence of many large 
corporations assure the successful continuance of this work. 
Space limits our comments to a few illustrative cases only. 
Most firms that employ many men find at the close of a month, 
six months, or a year, numerous misfits who must either be 
dismissed or transferred to other branches of the business, where 
the trial continues. This constant " turnover" of employees 
means a great sacrifice for the firm in time, money, and efficiency. 
It is possible to devise tests to be applied to seekers of employ- 
ment which will eliminate much of this waste. These tests are 
so arranged that they involve the habits and capacities required 
in a particular trade, such as telephone work, salesmanship, 



58 GENERAL PSYCHOLOGY 

expert gunner's work, etc. Each of these series of tests, in 
order to be rated as valid, must detect the salesmen, e.g., 
whom the firm has already found to be the most successful 
and also those who have proved to be the least so. No test or 
scale of tests can go back of this criterion of validity. The 
psychologist makes no effort to go behind the firm's own experi- 
ence concerning the men who have proved most successful in 
their work; but he uses the rating of these men on his tests 
in improving and standardizing his scale. Such a general pro- 
cedure is a vast improvement over the present methods, because 
it enables the employer to determine in a short time and at a 
minimum cost that which at present he can learn only after 
employing a man for a period of months or years. 

As an example of the procedure we can give the test applied 
to telephone girls by Miinsterberg. The problem was to devise 
tests that would detect those girls who held out promise of being 
successful in their work. Thirty women were used, among 
whom, unknown to Miinsterberg, were some highly efficient 
operators placed there by the company. Sample tests used 
were as follows: (i) The auditory memory span was determined. 
This is the greatest number of digits that one can write down 
after having heard them slowly pronounced once. Numbers 
ranging from 4 digits to 12 digits were used. (2) Attention 
was measured by requiring the subjects to cancel out each a 
on a newspaper page. Six minutes were allowed and grades or 
scores were given on the basis of the amount and quality of 
work. (3) Space perception and the ability to make rapid 
accurate movements were tested. (4) Each girl was required 
to sort rapidly a complicated series of cards. The girls were 
ranked according to their ability in these and similar tests, and 
after three months these results were correlated with the experi- 
ence of the telephone company. It was found that the subjects 
who ranked high in the actual telephone work also ranked high 
in the tests. 



INDIVIDUAL AND APPLIED PSYCHOLOGY 59 

Business is interested not only in the employment of indi- 
viduals capable as operators, clerks, salesmen, etc., but it is 
interested in sales brought about through the medium of adver- 
tising. An advertisement is a stimulus to response and is 
therefore subject to careful psychological analysis. Experi- 
mentation along this line has been well begun by such psychol- 
ogists as Scott, Strong, Hollingworth, Adams, and others. Of 
the many problems available for study we may list the follow- 
ing: What is the effect on the selling power of the advertisement 
of the following factors: (a) the location on the page; (b) the 
frequency of its appearance; (c) the character of the type; 
(d) the character of the illustrations; (e) the colors employed; 
(/) the various types of descriptive reading, etc.? In performing 
these experiments suitable advertisements are used in such a 
manner that as nearly as possible only one factor shall be tested 
at a time. The "selling power" is measured under laboratory 
conditions in terms of what the subjects say concerning the 
appeal made by the various cases and in terms of what memory 
tests show of the different degrees to which the retention of the 
advertisement is affected by the factors concerned. Data so 
secured from a large number of observers can be of great 
economic value in business. To be of the greatest value, how- 
ever, the results so secured should be checked up by actual 
selling returns for the different advertisements. In some cases 
this has been possible, and the outcome has held out encourage- 
ment for further study. 

Conclusion. — 'The present chapter has been devoted to an 
exposition of certain practical fields of psychology. The sub- 
ject is rapidly growing and is one that is expanding particularly 
under the stimulus of war conditions. In addition to the prac- 
tical phases of individual and applied psychology, the chapter 
has given concrete data upon the variations of human nature 
as they concern the individual. The significance of such data 
was commented upon at the beginning of this chapter. Our 



60 GENERAL PSYCHOLOGY 

next study will be of the individual from the point of view of his 
abnormal behavior, the field where psychology and medicine 
come most closely together. 

REFERENCES . 

Adams, H. F. Advertising and Its Mental Laws. New York: 191 6. 
Davenport, C. E. Heredity in Relation to Eugenics. New York: 

1911. 
Goddard, H. H. The Kallikak Family. New York: 191 2. 
. Feeble-mindedness. Its Causes and Consequences. New 

York: 1914. 
Hollingworth, H. L. Vocational Psychology. New York: 191 6. 
Miinsterberg, Hugo. Psychology and Industrial Efficiency. Boston: 

1913. 
Pintner, R., and Paterson, D. G. A Scale of Performance Tests. 

New York: 1917. 
Scott, W. D. Increasing Human Efficiency in Business. New York: 

1911. 
. The Psychology of Advertising. Third edition. Boston: 

1912. 
Seashore, C. E. Psychology in Daily Life. New York: 19 14. 
Stern, W. "The Psychological Methods of Testing Intelligence." 

Trans, by Whipple, Edu. Psych. Mon. (1914), No. 13. 
Terman, L. M. The Measurement of Intelligence. Boston: 1916. 
Thorndike, E. L. "Scientific Personnel Work in the Army," Science, 

N.S., LXIX (1919), 53-6i. 
Walter, H. E. Genetics: An Introduction to the Study of Heredity. 

New York: 1913. 
Whipple, G. M. Manual of Mental and Physical Tests. 2 vols. 

Baltimore: 191 5. 
Yerkes, R. M., Bridges, J. W., and Hardwick, Rose. S. A Point 

Scale for Measuring Mental Ability. Baltimore: 191 5. 
Yerkes, R. M. "Psychology in Relation to the War," Psychological 

Review, XXV (1918), 85-115. 



CHAPTER III 
ABNORMAL PSYCHOLOGY 

Problems. — The field of abnormal psychology has long 
included a list of more or less unrelated problems, the claim for 
treatment of many of which lay in their unusual and mystic 
character. Here would belong particularly telepathy and 
spiritualism. Other problems, however, dealing with mental 
disease and the analysis of the less obvious forces of human 
nature rightly hold the positions of chief importance in the 
field. Here one finds a body of topics involving a growing 
accumulation of solid fact which is intimately bound up with 
individual and social welfare. The problems especially involved 
are those of multiple personality, hysteria, certain insanities, 
the inheritance of mental defects, dreams, and psychoanalysis. 
This is the series of topics which we shall examine briefly in our 
attempt to formulate a picture of human nature as it deviates 
markedly from the normal in the direction of disease. The 
present chapter, accordingly, is closely related to the preced- 
ing one, "Individual Psychology," which in so far as it dealt 
with feeble-mindedness dealt also with the subnormal. The 
dominant principle in the phenomena now to be studied is 
that of the disintegration, or splitting up, of consciousness 
into separate parts. On the physical side we are to assume the 
dissociation of the nervous processes underlying behavior. 
The most striking examples of this dissociation are the scientific 
cases which are very similar to the story of Dr. Jekyll and 
Mr. Hyde. Later in the discussion we shall have occasion to 
analyze these in detail. 

The normal human individual is judged by his ability to 
adjust himself with average success to his own environment. 

61 



62 GENERAL PSYCHOLOGY 

When we speak of mental diseases we refer to chronic cases of 
maladjustment to the environment. In many instances definite 
defects (lesions due to tumors, accidents, and disease) can be 
found in the nervous system which can be correlated with the 
mental disturbance according to the principle of cause and 
effect. These are the structural psychoses. Functional psy- 
choses, or neuroses, do not reveal an accompanying nervous 
defect. There is every reason for assuming its presence, how- 
ever, and for attributing our inability to detect it to our present 
inadequate methods of search. As examples of the structural 
neuroses we may think of cases of general paresis, whose cause 
is a syphilitic infection and subsequent destruction of brain 
tissue. This is the great outstanding structural neurosis, and 
we shall have occasion later in the chapter to describe both 
its mental and physical sides. Most of our study, however, will 
concern the functional neuroses. It is here that we come closest 
to the average daily experience of normal human beings. Here 
we find hysteria, paranoia, dementia precox, and other dis- 
turbances. Less abnormal are dreams, morbid fears, and the 
many cases of slips of speech and forgetting that insistently 
appear in daily life. 

Defense Mechanisms. — The transition from the normal to 
the abnormal is very gradual and may well engage our atten- 
tion through a discussion of defense mechanisms. It may well 
be stated as a universal principle that each individual is in 
constant conflict with other individuals and with various parts 
of his own individuality. He is a constant applicant for the 
approbation of others, for their respect, and for superiority over 
them. Furthermore he must retain respect for himself. His life 
must be valuable in his own eyes. Any experience with himself 
or others, or any memory of such experience, that tends to detract 
from the foregoing desires is unpleasant, tending to arouse 
fear, shame, remorse, regret, and other similar emotions. The 
unpleasant and the painful tend to be avoided by one means 



ABNORMAL PSYCHOLOGY 63 

or another. The simple organism may leave an environment 
that is too hot or cold and so defend itself from certain forms of 
pain and unpleasantness. Likewise, man may leave the society 
of other persons who refuse to look upon him with favor. In 
these social cases, however, where other selves are involved, not 
only is the individual haunted by the memory of past dis- 
approvals, but he has also thrust himself into another social 
group where the same experience will probably be repeated. 
He cannot avoid his fellows entirely any more than he can fly 
from himself and his own unpleasant fears and reproaches. 

In these cases where flight from conflict is useless or impos- 
sible, an individual constructs more or less consciously a system 
of defense mechanisms which serve to keep the unpleasant occur- 
rences from invading consciousness. These defenses may take 
the form of elaborately thought out systems of ideas. One 
may find, e.g., a case where an individual, in order to avoid 
admitting his own incompetence, builds up the delusion of being 
persecuted by all whom he meets. He cannot hold his job. 
He goes from one field of employment to another, constantly 
driven — so he makes himself believe — not by his own short- 
comings but by the envy and persecution of his associates. 
Systems of philosophy, while they are much more valuable 
socially than systems of delusions of the type just indicated, 
are also psychic shelters from the storms of conflict with an 
unfriendly world. The Stoics and Epicureans of the Greek 
and Roman age sought consolation and dignity in an ideal world 
when the real world seemed prone to fall to pieces about their 
ears. Similarly, the child who is shy and non-self-asserting may 
build up a mythical world of companions where he goes for play 
and comradeship. It is no rare thing for such a "defense" to 
last over into adult life. Furthermore, beautiful women and 
large robust men who may feel their mental shortcomings fall 
back upon poses and domineering attitudes as defense mecha- 
nisms for their self-esteem. Comfortable people who should 



64 GENERAL PSYCHOLOGY 

have economized as a patriotic duty during the Great War and 
who should have felt shame at being "unpatriotic" shielded 
themselves behind many excuses in order to gratify their desires. 
Thus the theater became necessary to maintain their spiritual 
morale; their automobiles must not depreciate from rust as 
gasoline mounted in price; and as for expensive dishes, "Why, 
one must not let the caterer starve, poor man!" 

In the realm of disease, imagined pains appear which serve 
to ward off the undesirable. Backaches and headaches, pains 
in the eyes and elsewhere, keep the willing patient from his task. 
"The further advanced neurotic who already spends life in bed 
and thinks it monotonous to be alone, gets peculiar attacks in 
which, for example, he rushes to the window and tries to throw 
himself out; these attacks necessitate the continual presence 
of a nurse, in spite of the fact that the family can little afford 
the luxury. A poor woman who suffers from her insignificant 
position in life, often when she comes to any new place, has a 
habit of attempting suicide, so that everyone is frightened and 
she is thus made a topic of general conversation, as if she were 
some great celebrity — so for a time she is assured against the 
pangs of obscurity." 1 

As opposed to these more or less highly elaborated defense 
mechanisms is the simple one of forgetting. The thing which, 
if remembered, would cause unpleasantness or would arouse 
shame, remorse, lack of self-esteem, etc., drops from conscious- 
ness in accordance with an unconscious wish to be free from it. 
The recognition of this fact clears up many lapses of memory 
in daily life and many of the strange amnesias (instances of 
forgetting) of mental disease. Father constantly forgets to 
pay the bill for mother's hat. He may attempt to use his office 
key in the home door, having forgotten where he is in accordance 
with his subconscious wish to be back at the office. One may 

1 P. Bjerre. History and Practise of Psychanalysis (Boston: 1916), 
p. 141. 



ABNORMAL PSYCHOLOGY 65 

persistently insult an acquaintance by forgetting his name, thus 
indicating that he is of little importance. Likewise in the 
field of dreams the illustrations are legion. Painful incidents 
tend to be forgotten, and consciousness is thus saved an experi- 
ence of shame, horror, and the like. In the field of mental 
disease the interpretation and the analysis of amnesias are 
particularly important. We shall discuss these cases under the 
topic of hysteria. 

One further "normal" case may be cited by way of pointing 
out the mechanism of these instances of forgetting. In the 
lectures on a course in psychology, it was my custom to describe 
a certain experiment performed on the brain of a man while he 
was fully conscious. The surgeon's name was X. One session 
when the lecture was being given it was found that the name X 
was completely forgotten. In analyzing this unusual case of 
amnesia first one associated idea and then another occurred, 
until suddenly the name of Y appeared in consciousness. The 
explanation was then clear. Y was a close friend whose child 
had been suspected of being hydrocephalous. This was very 
distressing both to the parents and to the circle of friends. This 
unpleasant experience I had intentionally repressed and for- 
gotten. Y took the child to X for diagnosis, and so X became 
associated in my mind with the unpleasant occurrence and was 
repressed and forgotten also. Even after this analysis I could 
not recall X's name. When it was looked up in a treatise on 
neurology, the name appeared totally strange and unfamiliar, 
so thoroughly had it been driven from consciousness. 

The concept of defense mechanisms owes much to Adler, 
who has shown the intimate connection between "organ inferi- 
ority" and the mental life. The child or adult person who feels 
himself neglected, or ugly, or unloved, and consequently inferior, 
builds up a psychic compensation. He seeks refuge possibly 
by constructing an ideal world where he is not neglected or 
ugly, or he may remind himself of his own intellectual superiority 



66 GENERAL PSYCHOLOGY 

or the goodness of his deeds. Likewise, one whose vision is 
defective compensates for the fact by an acquired delicacy of 
touch or hearing. One who fears his lungs are weak may 
develop many mental peculiarities growing out of a solicitous 
attitude toward his respiratory apparatus, and he may, indeed, 
in combating his inferiority, develop a powerful physique. 
Defense mechanisms as described in this section afford the 
explanatory cue to many characteristics of the mental diseases 
to be described below. 

Types of Mental Disease. — Just as it is impossible to 
separate sharply the normal from the diseased mental condi- 
tions, so it is impossible to draw any fixed lines between the 
different types within the field of mental disease itself. Descrip- 
tively the best one can do is to enumerate certain broad char- 
acteristics that appear to dominate in the more fundamental 
diseases. Therapeutically one must take each case on its own 
merits and deal with mental abnormalities in protean form. We 
may, however, follow Jelliffe and White (191 5) in listing the 
chief mental diseases. Hysteria, compulsion neurosis, anxiety 
neurosis, and neurasthenia may be placed in a first group, 
termed by Freud the psychoneuroses and actual neuroses. 
Then may be listed a miscellaneous group: maniac-depressive 
psychoses; paranoia; epilepsy; dementia precox; psychoses 
due to infection, exhaustion, or poison; psychoses associated 
with such diseases as apoplexy, heart disease, chorea, etc. ; and 
pre-senile, senile, and arterio-sclerotic psychoses. To these we 
shall add paresis. Jelliffe and White also add idiocy, imbecility, 
and feeble-mindedness, and we may recognize that these topics 
concern the field of mental disease as well as that of individual 
psychology. It is permissible, however, to separate the last 
three from the former list for the following reason: In idiocy, 
imbecility, and feeble-mindedness one deals with individuals 
who have failed to develop normal capacities of adjustment. 
In the other diseases or defects the individuals are suffering 



ABNORMAL PSYCHOLOGY 67 

from a loss of capacities that they once enjoyed. Obviously 
we shall be unable to deal even by definition with all the forms 
of mental disease listed above. Accordingly our purpose will 
be to sketch the bare outline of a few. 

In the general class of mental disorders listed above, 
clinicians, as we have said, recognize a group of functional 
neuroses and one of structural neuroses. It is important that 
the continuity of nervous and mental diseases be appreciated. 
It is only in a transferred sense or by analogy that we speak of 
a "mental" disease, for the disease always rests upon the mal- 
functioning of nerve mechanisms. The two groups of defects 
may for practical purposes, however, be distinguished on the basis 
of apparent destruction of nerve tissue. Those mental diseases 
are "functional" in nature where present methods of search 
reveal no defects in nerve structure which might cause them. 

Causes of Nervous and Mental Disease. — The causes of 
nervous and mental diseases are legion. Whatever interferes 
with the normal functioning of the nervous system produces 
nervous disease or defect and may also produce disturbances 
in consciousness. In such a list one may place: accidents, 
e.g., falls and wounds; hereditary or congenital defects; in- 
fectious diseases, e.g., scarlet fever, diphtheria, tuberculosis, and 
particularly syphilis; alcoholism; poisonings incident to certain 
occupations, e.g., lead and mercury poisonings; moral shocks, 
etc. Individuals vary greatly in their resistance to these 
disturbing factors. What will produce delirium, hallucina- 
tions, paranoia, or dementia in one person may leave another 
unaffected. The strain of nursing a parent during a fatal 
illness may produce hysteria in one person and only temporary 
exhaustion and distress in another. Syphilitic infection in one 
person may result in tabes, paresis, or other defect and in another 
may never manifest itself in the realm of nervous and mental 
disease. This lack of resistance may be termed an instability 
of nervous organization and is inherited. 



68 



GENERAL PSYCHOLOGY 



The importance of heredity as a determining factor in any 
given case of disease can hardly be overestimated. We have 
had this brought to our attention already in the case of the 
Kallikak family which was presented in the foregoing chapter. 
This inheritance rests upon variations in the germ plasm of the 
individual, and is not a social inheritance in the sense that 
customs and traditions are. The social conditions surrounding 











ill 










Fig. 14. — A lateral view of the brain in paresis (after Jelliffe and White) 

the individual will determine largely the detailed content of his 
psychosis (abnormal mental state), i.e., they will determine the 
objects of his morbid fears; but they will not be the fundamental 
conditions of the disorder. 

Paresis. — From the large field of mental disease we shall 
select four topics: paresis, paranoia, multiple personality, 
and hysteria. A brief presentation of these will give us much 
information concerning the abnormal phases of human nature. 
Let us first consider paresis. 



ABNORMAL PSYCHOLOGY 69 

Paresis, or progressive general paralysis, is a nervous and 
mental disease correlated with a certain type of cerebral syphilis. 
On the physical side there is not so much a paralysis as there is 
a general weakness. On the mental side progression is made 
in various typical ways to a final dementia, or loss of mentality. 
This gradual change may extend over a period of from one 
to five years. It is practically uniformly fatal. Apparent 
recoveries or remissions are usual, only however to be followed 
by a relapse and a fatal termination. Most frequently the 
disease appears in middle life, although juvenile paresis is also 
common. Figure 14 shows a lateral view of the brain with wide- 
spread destruction of its surface in paresis. This will be more 
apparent if the reader will compare the present figure with the 
one on page 1 50, which shows a different, but comparable, view 
of a normal brain. 

Quotation may be made from Church and Peterson (1908) 
in description of the early symptoms: 1 

General paresis is one of the most insidious forms of insanity as 
regards its gradual, almost unnoticeable onset. Very often this 
early stage presents symptoms which lead to its being mistaken for 
neurasthenia. Indeed, the earliest symptoms may be neurasthenic 
in character, or even a combination of hysteria with neurasthenia. 
Sleeplessness, tremor, irritability of mood, hypochondriacal depres- 
sion, dull headache, ophthalmic migraine, pains in various parts of 
the body, general malaise, loss of appetite, and digestive disorders — 
these are the manifestations which may be readily misinterpreted 
as purely of functional nature. It is only when other symptoms in 
addition to these are presented that a suspicion of a more serious 
malady may be entertained or the diagnosis actually established. 
These symptoms are, on the mental side: little faults of memory; 
errors in speech or writing; the misuse of words; the leaving out of 
letters, syllables, or words, or their reduplication in writing; growing 
indifference to the higher sentiments; loss of the critical faculty; 

1 A. Church and F. Peterson. Nervous and Mental Diseases (Phila- 
delphia: 1908), p. 832. 



70 GENERAL PSYCHOLOGY 

small lapses in the proprieties, and failure of interest in the more 
important affairs of life. As these mental features become more and 
more pronounced, the patient loses and mislays things, makes mis- 
takes in money matters, errs in appointments, confuses persons and 
objects, forgets his way, becomes easily angered, markedly offends 
the proprieties, shows extravagance in the use of money, evinces 
distinct loss of ethical feelings, exhibits proclivities to sexual and alco- 
holic excess, and becomes negligent of his dress. 

After this initial, or prodromal, period the above symptoms 
increase in intensity. Amnesias (memory losses) become 
greater. Grandiose or depressed delusions become more 
striking; excesses more frequent and serious. On the bodily 
side many disturbances appear of which the following are 
typical: muscle tremors, particularly in the tongue and face; 
speech defects leading to a "drunken speech"; failure of the 
pupils of the eyes to contract to an increase in light intensity 
(Argyl-Robertson pupils); epileptiform or apoplectiform con- 
vulsions; and disorders of the hair, skin, and bone (trophic 
disorders). In the final stages the dementia becomes more 
and more profound, physical helplessness is usually complete, 
and death follows. 

Paranoia. — Paranoia presents a very different picture from 
that just drawn for paresis, which is a structural disease. No 
changes can be found in the nervous system with which to 
correlate paranoia. It is therefore a functional disease. The 
heredity of paranoid patients shows marked neuropathic 
(abnormal nervous) tendencies. The disease itself may be 
characterized as one of chronic systematized delusions. Loss 
of mental power (dementia) is not usual until the later stages 
of the disease. It is very doubtful whether cures are possible 
and usually confinement in an institution is required, depending, 
however, upon the nature and intensity of the delusions. Many 
"cranks" and "peculiar" people that one constantly meets 
either are suffering from paranoia or are what may be termed 



ABNORMAL PSYCHOLOGY 71 

■paranoid characters. People who have had a single fixed idea 
largely elaborated, who have regarded themselves as persecuted 
and as set apart from their fellows in ability and character, are 
paranoiacs. In this group can be found many leaders who have 
won distinction in war, politics, and religion. The treatment 
of the disease consists in change of scene, hard outdoor work, 
and general diversion. 

Krafft-Ebing subdivides paranoia, as it appears after ado- 
lescence, into the following types on the basis of the nature of 
the delusions: 

A. Paranoia persecutoria: 
.a) the typical form, 

b) paranoia erotica, where the delusions are those 
of love and consist largely in the belief that 
others are in love with the patient and are perse- 
cuting him, 

c) paranoia querulans or the type that is always 
engaging in lawsuits and quarrels. 

B. Paranoia expansiva: 

a) paranoia inventoria and reformatoria, 

b) paranoia religiosa, 

c) paranoia erotica in expansive form. 

There seems to be good reason to believe that the system- 
atized delusions of paranoia are defense mechanisms. Here, 
e.g., is a person who drifts from one job to another, failing at 
first from inability. Rather than admit his own inferiority, 
he begins to note seemingly suspicious behavior among his 
associates. They are spying upon him. They are carrying 
tales. They tamper with his work. Perhaps he reports the 
matter to his employer. Finally he is dismissed, and then he 
repeats the behavior in other situations. People soon begin 
to notice his peculiar actions, and their attention increases his 
persecutory delusions. Because his pains are many, he must 
have many enemies. Indeed, he is pursued by organized bands 



72 GENERAL PSYCHOLOGY 

and groups. He may now hit upon the suggestion that the 
persecution results from his own great superiority — his asso- 
ciates are jealous of his skill. He is a Messiah, or the world's 
greatest soldier, or inventor, or what not. His manly char- 
acteristics are such that he is passionately loved by a beautiful 
lady whom his enemies prevent from coming to him — endless 
indeed is the list of delusions the paranoiac may have. Auditory 
hallucinations are common. The patient's enemies talk about 
him maliciously even at night when he tries to sleep. He hears 
their voices although his persecutors remain unseen. The 
paranoiac may or may not react to his fancied persecutions in 
a way dangerous to himself or others, and a final stage of 
dementia may or may not close the chapter of his life. 

Multiple Personality. — The study of multiple personality 
offers another example of functional psychoses. In a sub- 
sequent chapter we shall have occasion to discuss in some detail 
the nature of the self or personality of the normal individual. 
Here it is important to indicate certain more or less abnormal 
changes that may appear in this self. The average individual 
regards himself as a unitary being. He remembers the major 
portion of the things he encounters and of the actions that he 
performs. He has organized his behavior to such an extent 
that no feeling of strangeness attaches to the fact that his 
actions on the baseball field are governed by different standards 
from those which control his conduct in business or in the home. 
In a very true sense it can be said (as we shall see) that even 
though this individual's experiences are the possession of a 
single person, just as truly they may be regarded as belonging 
to three persons — a baseball self, a business self, and a home 
self. This view is justified by the fact of the three different 
standards of conduct that are used and by the fact of the very 
different interests of each self. It sometimes happens that the 
separation between the selves becomes so great that when one 
self is dominant no memory of the other selves exists; or, even 



ABNORMAL PSYCHOLOGY 73 

if the others are remembered, they are recognized as so different 
from the one dominant at the time that no question is raised 
in the mind of the individual whether or not there is really 
more than one self involved. Stevenson's story of Dr. Jekyll 
and Mr. Hyde is an instance well known to the laity. A few 
people are met in daily life who approximate this condition, 
and the annals of science contain many demonstrated cases. 

Multiple personality, as we have said, is a functional mental 
disease. It is closely related to hysteria, and is regarded by 
the eminent French psychologist Pierre Janet as identical with 
that psychosis. Like paranoia these mental disorders are 
striking reminders of salient features in everyday normal life. 
An American psychologist, Dr. Morton Prince, has written 
(1905) a very fascinating account of a Miss Beauchamp, 1 who 
came under his care and who finally proved to be a composite 
of four different personalities. All four of these selves, of course, 
used the same body, but each must be regarded as employing 
a different organization of units within the brain. In the follow- 
ing quotations we shall present some of the chief characteristics 
of this most interesting case. 

It was said in the beginning that, in addition to her normal self, 
and the hypnotic state known as B II, Miss Beauchamp may be any 
one of three different persons, who are known respectively as B I, 

B III, and B IV The numbers were affixed to the personalities 

as they were chronologically discovered. That is to say, when 
Miss Beauchamp first came under observation she was known of 
course by her own name. Later, when she was hypnotized, her 
mental state in hypnosis was known as the hypnotic self. Every- 
thing was then simple enough, for we had to do only with a person 
awake and hypnotized, and no extended nomenclature was required. 
Later, when another mental state was discovered, it became necessary 
to have distinguishing terms; so Miss Beauchamp was called B L 
the hypnotic state B II, and the third state (at first thought to be a 

1 Morton Prince. The Dissociation of a Personality (New York: 1905)- 



74 GENERAL PSYCHOLOGY 

second hypnotic state, but later proved to be a personality) was 
named B III. Still later, a fourth state developed and was termed 
BIV. 

B I was known as Miss Beauchamp. 

Bill was known as "Chris," in distinction from "Christine," 
the Christian name of Miss Beauchamp. Later, Chris took the name 
of Sally. 

B IV had no other name, although Sally dubbed her "the Idiot." 

Now these three personalities had very sharply defined traits 
which gave a very distinctive individuality to each. One might say 
that each represented certain characteristic elements of human nature, 
and that the three might serve as an allegorical picture of the tend- 
encies of man. If this were not a serious psychological study, I might 
feel tempted to entitle this volume "The Saint, the Woman, arid the 
Devil." The Saint, the typical saint of literature, is B I. Her char- 
acter may fairly be said without exaggeration to personify those traits 
which expounders of various religions, whether Christian, Buddhist, 
Shinto, or Confucian, have held up as the ideals to be attained by 
human nature. To her mind selfishness, impatience, rudeness, 
uncharitableness, a failure to tell the truth or a suppression of half 
the truth were literally sins, and their manifestation wickedness, 
to be cast out by fasting, vigils, and prayer. She frequently makes 
allusion to such sins in her letters. B IV is the Woman, personifying 
the frailties of temper, self-concentration, ambition, and self-interest, 
which ordinarily are the dominating factors of the average human 
being. Her idea in life is to accomplish her own ends, regardless of 
the consequences to others, and of the means employed. Sally is the 
Devil, not an immoral devil, to be sure, but rather a mischievous imp, 
one of that kind which we might imagine would take pleasure in 
thwarting the aspirations of humanity. To her pranks were largely 
due the moral suffering which B I endured, the social difficulties 
which befell B IV, and the trials and tribulations which were the lot 
of both. 

Not the least interesting of the curious nervous phenomena mani- 
fested, are the different degrees of health enjoyed by the different 
personalities. One would imagine that if ill health were always based 
on physical alterations, each personality must have the same ailments; 



ABNORMAL PSYCHOLOGY 75 

but such is not the case. The person known as B I has the poorest 
health; B IV is more robust, and is capable of mental and physical 
exertion without ill effects, which would be beyond the powers of B I; 
while B III is a stranger to an ache or pain. She does not know 
what illness means. 

This personality, Sally, like the others at times is an alternating 
personality. But, besides this, at other times it is a group of disso- 
ciated conscious states, which, existing simultaneously with the 
primary self, whether B I or B IV, is technically termed a subcon- 
sciousness — a subconscious personality. This subconscious per- 
sonality and the waking personality together represent a doubling 
of the mind. But this doubling exists because certain mental states 
have been dissociated from the main stream of consciousness and 
have acquired a more or less independent existence, and form an 
extra mind. As a result of long years of experience, the acquisition 
of long chains of memories, this second stream has acquired a wide 
field of mental life. Nothing of this life is known to the main stream 
of consciousness. 1 

These four selves had a curious relationship one to the 
other. B I knew only herself. B II knew herself and also B I, 
i.e., in reality knew the actual thoughts of B I without being 
told. B III knew herself and each of the first two. B IV 
knew only herself and was only known to B III through her 
actions. When we speak of B I's not knowing the other selves, 
we are pointing out remarkable instances of amnesia, or 
forgetting. All of these selves exist in the same body, but 
when B I, for example, is uppermost the other selves are 
forgotten and are absent. From the standpoint of conscious- 
ness they are non-existent. They persist only in a physical 
sense as changes of the brain. B III, however, knows what 
she herself thinks and can remember the thoughts and actions 
of B I. Without making quotations one can readily under- 
stand how at a loss and even how embarrassed B I might 
be by the situations into which B III might lead her. 

1 Morton Prince, op. tit., pp. 15-18. 



76 GENERAL PSYCHOLOGY 

Particularly must this be the case since B III is the mischievous 
imp that she is. 

We have not space to follow the history of this case through 
its many windings to the final discovery by Dr. Prince of who 
the real Miss Beauchamp was. We must be content with the 
final outcome. B II was the real girl, only asleep (hypnotized) . 
B I and B IV were the disintegrations of B II. Sally (B III) 
was an alternating personality to the real Miss Beauchamp. 
With the latter's final constant existence Sally disappeared. A 
description of B II can be given best in the words of Dr. Prince: 

[B II] was a person so different from B I and B IV, so natural and 
self-contained, and so free from every, sign of abnormality that there 
could be no doubt that I had again the Real Miss Beauchamp. There 
was none of the suffering, depression, and submissive idealism of 
B I; none of the ill-temper, stubbornness, and reticent antagonism 
of B IV. Nor was there any "rattling" of the mind, hallucinations, 
amnesia, bewilderment, or ignorance of events, as had been the case 
in the earlier experiments. She knew me and her surroundings and 
everything belonging to the lives of B I and B IV. She had the mem- 
ories of both. 1 

Hysteria. — Since the extended case-history which we have 
just given is in reality one of hysteria, our present account may 
be brief. Janet and Freud are the chief authorities on this 
defect. The former has contributed particularly to the descrip- 
tive analysis, and the latter to the explanatory analysis of the 
problem. We shall first summarize the topic as Janet views it. 

Hysteria is characterized by great suggestibility resulting 
in a tendency toward the breaking away from consciousness of 
systems of ideas and functions. We saw the dissociation on a 
grand scale in the case of Miss Beauchamp. It may, however, 
be of any magnitude. It may merely take the form of slight 
recurrent muscular twitchings (tics) either in isolated muscles 
or in the hands, shoulders, etc.; of somnambulisms; of hysteri- 

1 Morton Prince, op. cit., pp. 519-20. 



ABNORMAL PSYCHOLOGY 77 

calfits and seizures; or of long nights (fugues) that may suddenly 
take the patient from his work and result in his waking from 
the trance in some distant locality without knowledge of how 
he came there. Furthermore this dissociation may be either 
positive or negative in its expression. Novel movements, as 
just described, may occur, or the effect may be a paralysis. 
Likewise in the realm of sensation the hysterical person may 
not only hear, see, or feel strange things, i.e., have hallucina- 
tions, but he may fail to receive sensations when he is touched 
(anaesthesia), or when objects are presented to his other sense- 
organs. These paralyses and anaesthesias are the result of sug- 
gestion and may appear suddenly. They do not depend upon 
an injury to the body. They have been described as the expres- 
sion or effect of subconscious ideas; but this explanation is 
unnecessary, for we need only assume that certain brain 
processes become separated from other neural processes and 
continue to function as though normal. A patient, for example, 
may encounter the suggestion that she cannot move her leg 
or that her foot is insensitive, and immediately the idea becomes 
a reality, i.e., she becomes either paralyzed or anaesthetic. In 
the Middle Ages anaesthetic areas of this type were well known 
and were regarded as indications that the person was a witch 
or possessed of devils. As we know, a conventional method 
of "witch discovery" was to explore the subject's skin with a 
needle for insensitive spots. 

In concluding the descriptive illustrations of the splitting 
off of ideas or systems of ideas, let us give a case in Janet's own 
words: 

We come back to the common story of a young girl twenty 
years old, called Irene, whom despair, caused by her mother's death, 
has made ill. We must remember that this woman's death has been 
very moving and dramatic. The poor woman, who had reached the 
last stage of consumption, lived alone with her daughter in a poor 
garret. Death came slowly, with suffocation, blood-vomiting, and 



78 GENERAL PSYCHOLOGY 

all its frightful procession of symptoms. The girl struggled hope- 
lessly against the impossible. She watched her mother during sixty- 
nights, working at her sewing-machine to earn a few pennies necessary 
to sustain their lives. After the mother's death she tried to revive 
the corpse, to call the breath back again; then, as she put the limbs 
upright, the body fell to the floor, and it took infinite exertion to lift 
it again into the bed. You may picture to yourself all that frightful 
scene. Some time after the funeral, curious and impressive symptoms 
began. It was one of the most splendid cases of somnambulism I 
ever saw. 

The crises last for hours, and they show a splendid dramatic per- 
formance, for no actress could rehearse those lugubrious scenes with 
such perfection. The young girl has the singular habit of acting 
again all the events that took place at her mother's death, without 
forgetting the least detail. Sometimes she only speaks, relating 
all that happened with great volubility, putting questions and 
answers in turn, or asking questions only, and seeming to listen for 
the answer; sometimes she only sees the sight, looking with frightened 
face and staring on the various scenes, and acting according to what 
she sees. At other times, she combines all hallucinations, words, 
and acts, and seems to play a very singular drama. When, in her 
drama, death has taken place, she carries on the same idea, and makes 
everything ready for her own suicide. She discusses it aloud, seems 
to speak with her mother, to receive advice from her; she fancies she 
will try to be run over by a locomotive. That detail is also a recollec- 
tion of a real event of her life. She fancies she is on the way, and 
stretches herself out on the floor of the room, waiting for death, with 
mingled dread and impatience. She poses, and wears on her face 
expressions really worthy of admiration, which remain fixed during 
several minutes. The train arrives before her staring eyes, she utters 
a terrible shriek, and falls back motionless, as if she were dead. She 
soon gets up and begins acting over again one of the preceding scenes. 
In fact, one of the characteristics of these somnambulisms is that they 
repeat themselves indefinitely. Not only the different attacks are 
always exactly alike, repeating the same movements, expressions, 
and words, but in the course of the same attack, when it has lasted a 
certain time, the same scene may be repeated again exactly in the 



ABNORMAL PSYCHOLOGY 79 

same way five or ten times. At last, the agitation seems to wear out, 
the dream grows less clear, and, gradually or suddenly, according to 
the cases, the patient comes back to her normal consciousness, takes 
up her ordinary business, quite undisturbed by what has happened. 1 

When this return of the normal state has occurred there is 
a complete amnesia for what has taken place during the seizure. 
Here we see again the same characteristics of divided personality 
that impressed us in the case of Miss Beauchamp. 

Freud's conception of hysteria (dating from the initial study 
with Breuer in 1895), as we have said, is an explanatory one. 
The main question is, "Why should the amnesias exist?" for 
amnesias are the dividing lines for whatever dissociations there 
are within the individual. Freud answers this question with 
the concept of defense mechanism whose nature we have already 
sketched. Each individual is the scene for conflicts between 
fundamental tendencies. In order to unify itself and protect 
itself from unpleasantness, each system of ideas forgets or 
represses those that conflict with it. Thus in the hysterical 
case we have just described the young girl "forgot" her experi- 
ence in nursing her mother as a defense against unpleasantness. 
From time to time, however, this repressed material would be 
re-aroused and would undergo what Freud terms conversion into 
the physical symptoms of the hysterical seizure. Freud would 
further insist that if the psychoanalytic method, soon to be 
described, were applied to each case of hysteria, the results would 
indicate two additional characteristics: first, the presence of 
infantile material (reminiscences from the patient's childhood) ; 
and, second, a close relation to experiences belonging to the 
sex life of the patient. 

Freud's Conception of the Neuroses. — With the conclusion 
of our sketch of multiple personality and hysteria we are 
brought back to the topic of defense mechanisms with which 

1 P. Janet. The Major Symptoms of Hysteria (New York: 1907), 
pp. 29-31. 



80 GENERAL PSYCHOLOGY 

the present chapter opened. The last section has familiarized 
us already to a certain extent with Freud's views on mental 
disorder. We may now list the factors upon which he places 
emphasis in the explanation of mental defects and abnormalities 
as follows: (i) the repression (the driving from consciousness 
and therefore the forgetting) of any material that would lead 
to unpleasantness as a result of conflict with accepted standards 
of conduct; (2) the activity of accepted standards in the role of 
a censor; (3) the dominant place of sexuality, interpreted in 
its broadest significance, in the experiences producing conflict; 
and (4) the endeavor of the suppressed complexes or tendencies, 
disguised through symbols and condensation (abbreviation), 
to rise into consciousness by eluding the censor. 

The Psychoanalytic Method. — The analysis striven for by 
the psychoanalytic method is a dissection of the repressed com- 
plexes which are characteristic of all people and which are 
abnormally developed in the mentally diseased (psychotic indi- 
viduals). We may think of an individual's character after the 
analogy of an iceberg where the part out of water corresponds 
to that part of character of which the possessor is directly and 
immediately aware. The large portion beneath water-level 
will then correspond to the hidden and repressed elements in 
character. We are using the term character to denote the 
sum total of those forces that shape and determine conduct, 
and everyone will recognize that the great majority of these 
factors lie beyond immediate awareness. There is good 
reason for believing that nothing that is learned is ever 
completely forgotten. Furthermore no instinctive tendency 
is ever lost. The unpleasantness that may attach to much 
that is learned or to much that is instinctive will bring about 
its repression below the level of consciousness; but from this 
region of merely physiological processes in the nervous system 
the material will contrive to determine conduct and in that 
manner shape character. 



ABNORMAL PSYCHOLOGY 81 

Only a very special method can restore to consciousness 
experiences that were forgotten perhaps in infancy or early 
childhodd and that have always been severely censured. Such 
a method, however, has been found in free association as adapted 
to psychoanalysis. Any experiences that occur together be- 
come associated in such a way that when one re-enters con- 
sciousness the other tends to follow. Thus if one has the idea 
"cat," the idea "dog" will probably follow by virtue of past 
associations. With this fact as the basis of procedure, the free- 
association method requires the individual to report to the 
examiner every idea that enters consciousness. To eliminate 
distraction as much as possible the patient is placed in a 
comfortable (reclining) position and is instructed to take a 
passive, non-resisting attitude, permitting ideas to come as they 
will. Many associations will be painful and will appear only 
after a struggle with the censor (the patient's standards). 
Accordingly, the patient must be told explicitly that all ideas 
must be communicated to the examiner without reserve, else 
the search through the hidden elements of character cannot 
proceed. It can be readily seen that in the hands of a skilful 
examiner this method is certain to bring to consciousness prac- 
tically all of an individual's past experience, however indirect 
an association path must be followed. The great therapeutic 
value of psychoanalysis lies in the fact that when the origin 
and nature of a patient's morbid fears and worries are found 
and explained to him the symptoms gradually abate and may 
finally disappear; indeed, the cure of this type of abnormal, 
psychotic individual is largely a matter of re-education through a 
familiarity with his own personality. 

The psychoanalytic method is an outcome of the method 
of hypnotism as used by Wetterstrand, Charcot, and others in 
the last half of the nineteenth century. Hypnotism is a method 
of producing artificial cases of multiple personality through 
suggestion. The essential procedure is to so concentrate the 



82 GENERAL PSYCHOLOGY 

individual's attention upon a monotonous and unchanging 
stimulus that the individual's censor is gradually "put to 
sleep." As a result the person in the state of hypnosis accepts 
as true the ideas suggested by the experimenter. Objects 
may be seen where no objects are, and vice versa. Actions 
may be performed that ordinarily would be regarded as fool- 
ish by the subject. Things may be said that are utterly unlike 
his usual speech. After the hypnosis has been removed a 
total amnesia exists for the period of its extent similar to 
the condition we saw in multiple personality and hysteria. It 
has been found that commands given the subject during the 
hypnosis with instruction to carry them out after the normal 
waking consciousness has been reinstated (post-hypnotic 
suggestion) will be duly obeyed at the appointed time. In 
this manner the experimenter may suggest that the subject 
will no longer suffer from certain pains, or morbid fears, or 
evil habits, and frequently results of much value have been 
obtained. At times apprehension has existed lest hypnotism 
be used to further criminal designs. Unless, however, the per- 
son hypnotized is already suffering from a poor voluntary 
control and initiative (aboulia), there is little danger, for a 
vigorous censor can, and will, check conduct that tends to depart 
in a serious manner from the normal. 

In concluding the discussion of abnormal psychology (and 
it must be conceded that we have omitted many important 
topics, particularly dreams and dementia precox), we should 
repeat the statement that was made at the beginning of the 
book: no one field can be studied apart from the subject- 
matter of other fields. The picture that we have drawn of 
the abnormal individual is intimately linked with the picture 
that we shall have at the close of the book. Human nature 
is so complex that in order to understand and appreciate 
it the student must approach it from many sides. In the 
following chapter on "Social and Racial Psychology" we shall 



ABNORMAL PSYCHOLOGY 83 

make a further intensive study of human nature, this time with 
particular reference to the influence of race and society upon the 
individual. 



REFERENCES 

Adler, Alfred. The Neurotic Constitution. Trans, by Gliick and 

Lind. New York: 191 7. 
Ellis, H. The World of Dreams. Boston: 191 1. 
Freud, Sigmund. Interpretation of Dreams. Trans, by Brill. New 

York: 1913. 
— —'. Psychopathology of Everyday Life. Trans, by Brill. New 

York: 1914. 
Haines, T. H. "The Genesis of a Paranoic State," Jour. Abnormal 

Psych., XI (1917), 368-95. 
Janet, P. The Major Symptoms of Hysteria. New York: 1907. 
Jelliffe, S. E., and White, W. A. Diseases of the Nervous System. 

Philadelphia: 191 5. 
Jones, E. Psycho-analysis. New York: 19 13. 
Moll, A. Hypnotism. Fourth edition. London: 1897. 
Prince, Morton. The Dissociation of a Personality. Second edition. 

New York: 1908. 

. The Unconscious. New York: 1916. 

White, W. A. Outlines of Psychiatry. Fifth edition. New York: 

1915- 
. Mechanisms of Character Formation. New York: 1916. 



CHAPTER IV 
SOCIAL AND RACIAL PSYCHOLOGY 

I. SOCIAL PSYCHOLOGY 

General Problems and Points of View. — Men and most 
animals show marked differences of behavior when in the 
presence of other organisms, notably members of the same 
species. This is the fundamental fact of social psychology — 
inter stimulation and response. A strange ant entering an ant 
neighborhood calls forth characteristic behavior in the environ- 
ment. A monkey, confined in a cage alone, becomes a different 
animal upon the introduction of a companion. In man we 
find such responses as shyness, coyness, and either a comfortable 
relaxation or a strained effort to make an appearance. These 
are all instances of social behavior. Social psychology seeks 
to describe and explain all such cases. It studies customs, 
traditions, fads, fashions, conventions, the crowd, the public, 
and the mob. Furthermore it analyzes law, religion,' morals, 
language, and art, in order to indicate and appraise the 
psychological groundwork of these institutions. The prime 
prerequisite for carrying forward these investigations is an 
understanding of the nature of certain traits of the individual. 
Thus the social psychologist must understand original human 
and animal nature — the instincts and emotions — and must know 
how and to what extent it is possible to modify this original na- 
ture through the individual's experience. He must be familiar 
with the nature and workings of suggestion, imitation, and 
sympathy; and he must appreciate the activities of imagina- 
tion and thought. Out of this social study of the individual 
grows a conception of the self as it is determined by a social en- 
vironment — a condition of living from which none can escape. 

84 



SOCIAL AND RACIAL PSYCHOLOGY 85 

So far we have stated the problems of social psychology in 
objective, behavioristic terms with no reference to conscious- 
ness. Very little attempt is made to approach these problems 
from an analytical, structural point of view. The descriptions 
of experiences that are given, however, often recognize very 
explicitly consciousness and its right to a place in the field of 
psychology. Studies of conscience, of conversion, and religious 
experiences in general, descriptions of mobs and analyses of the 
social self, are cases where consciousness occupies a prominent 
place. 

The Nature of Society. — Ellwood has emphasized the view 
that by the term society is meant any psychic, or mental, inter- 
action of individuals. Mere physical proximity and interaction 
are not sufficient to constitute social behavior. Paramecia 
may congregate in a drop of chemical, but they are not thereby 
a society; nor does the fact that human beings are herded 
together in a city make of them a society. Whether the mar- 
velously complex activities of the ants and bees are social will 
depend, according to Ellwood, upon whether or not the inter- 
actions are conscious. This is a very important point of view 
and one into all of whose implications we cannot go. It is the 
distinction between consciousness and behavior meeting us 
again at a new angle. Current psychology includes both. The 
error comes, apparently, from the effort made to delimit sharply 
the social from the non-social. Inasmuch, however, as we have 
no certain method of detecting the presence and absence of 
consciousness in animals below man, we shall view as social 
behavior all cases where the conduct and behavior of an organ- 
ism is modified as the direct result of the action of another 
organism. The responses of one individual are themselves 
the stimuli for the responses of another individual. Accord- 
ingly, we may say that all animals enter into social relations. 
The most primitive cases are possibly the food and sex reactions 
of protozoa. In the account that is to follow, however, we shall 



S6 GENERAL PSYCHOLOGY 

confine our attention to certain selected topics from human 
social behavior. We shall, in fact, be led to see that practically 
all human responses are social. 

The Origin of Society. — It was held by Hobbes and Rous- 
seau that society is an artifact arising from a mutual contract 
between individuals when this finally becomes necessary for 
protection against mutual depredations. Such a view pre- 
supposes that there was a time when society, or social relations, 
did not exist and that social relations are to be limited to the 
fact of organized society and its phenomena. The present view 
would list as social even the "anti-social" facts of conflict. 

Society is as old as man himself. (We are now ignoring 
the animals below man.) It is implicit in mating, and is prom- 
inent when the family — or a permanent union of the sexes with 
the consequent care of children — arises. Whether primitive or 
advanced, society's phenomena revolve about the fundamental 
instincts of food and sex. Suggestion has already been made 
concerning the role of sex. It is necessary to point out further 
that the term sex must be interpreted in the broadest way, 
covering courtship, mating, family life, and the rearing and 
education of offspring. Even the most casual inspection will 
show to what an enormous extent social phenomena are con- 
cerned with these activities. The place of the food-getting 
impulse is equally prominent. In primitive times individuals 
and tribes migrated from localities where food was scarce and 
sought more fruitful areas. Permanent villages grew up in 
these places and in locations possessed of trade advantages. 
Farming, dairying, horticulture, and animal-breeding — all are 
occupations arising for the production of food. Distribution, 
requiring the necessary means of transportation, and the final 
consumption tell the story of all but a very minor portion of 
social activities. Back of all of them is the machinery of 
social forces and motives, the names of which (imitation, sug- 
gestion, etc.) we have already canvassed. 



SOCIAL AND RACIAL PSYCHOLOGY 87 

In our further discussion of social facts we shall work under 
two main headings: "The Self as Social" and "Social Institu- 
tions." In the study of the former topic we shall attempt to 
secure a thorough understanding of the social individuals whose 
behavior makes the social institutions. Under the latter topic 
we shall describe briefly only customs and mobs, leaving aside 
other topics of great importance such as religion, law, and 
morality. 

A. THE SELF AS SOCIAL 

The Place of Instincts in Social Life. — Any thorough 
account of the self must include a study of instincts because 
these are the fundamental forms of all behavior. By virtue of 
his membership in the species each individual possesses certain 
characteristic inherited modes of acting called instincts. Here 
belong such responses as fear, anger, joy, sorrow, grief, jealousy, 
gregariousness, acquisitiveness, food-getting, sex responses, etc. 
Once again, as in the chapter on "Animal Psychology," we must 
postpone the detailed consideration of instinct to Part II, and 
continue to think of it in the fairly general sense of any inherited 
form of response in animals possessed of a nervous system. 
The instincts are termed fundamental because all of the later 
developments in conduct (character) are composed of modi- 
fications of this original stuff of human nature. In a very true 
.sense the entire field of psychology centers upon this question 
of adjustment to environment, whether the adjustment be 
inherited or acquired. In the process of change and growth 
that goes on in each instinct, social factors are always effective. 
I learn to fear what my neighbor fears. I secure my food and 
mate in the ways prescribed by social usage. My curiosity and 
jealousy are aroused and satisfied in the conventional manner 
prescribed by the group in which I live. Wherever one turns 
he is met by social guidance and compulsion. In this respect — 
and it is an important one — all instincts are social. One may, 



88 GENERAL PSYCHOLOGY 

however, consider the instincts not so much from the stand- 
point of their conformity to social standards (or vice versa) as 
from the point of view of the types of situations that arouse 
them or of the primary functions that they serve. From such 
an angle sex, gregariousness, jealousy, the parental instinct, 
fear, and anger are social in a way that hunger, curiosity, and 
joy seldom are. The former instincts are aroused in situations 
where other persons are usually integral parts. Even in the 
case of anger where the social element is less uniform, there 
exists an inevitable tendency to personify the offending object. 
The elusive collar-button and the threatening cloud alike tend 
to become persons at the moment of the arousal of the instinct. 
This is also equally true of fear. The latter instincts of our 
foregoing list are not so essentially social. 

The chief importance of instinct for society lies in two 
directions: (i) The instincts furnish the fundamental driving- 
springs to action in the individual. They represent solutions 
for typical recurrent difficulties as they have been worked out 
in the past history of the species. Customs, traditions, con- 
ventions, fads — all must take this fact into account. These 
habits are built upon the basis of instinct and represent habitual 
modifications found desirable by the group of individuals. Thus 
marriage in its various forms is built upon the basis of the sex 
and parental instincts. Customs of food production and dis- 
tribution involve the instincts of hunger-satisfaction, rivalry, 
acquisitiveness, etc. These modifications and elaborations of 
instinctive responses are transmitted from generation to genera- 
tion by education, i.e., by social as opposed to physical heredity. 
(2) Not only do instincts represent the fundamental responses 
made by an individual to certain situations that constantly 
recur within his lifetime, but furthermore they are types of 
behavior that cannot be eliminated. One may repress or 
modify an instinct so that it seldom recurs or so that it appears 
in a highly modified form, but one cannot eradicate the instinct 



SOCIAL AND RACIAL PSYCHOLOGY 89 

totally. Social customs and usages, when they are successful, 
recognize this fact. The sex instinct cannot be eliminated or 
successfully repressed. The Middle Ages saw the failure of 
such a doctrine, and Freudianism at the present time is con- 
tributing further data. Hostility, jealousy, rivalry, and the 
other instincts are likewise permanent features of the organism's 
behavior system. Social groups can modify but cannot destroy 
these tendencies. Hostility may be sublimated from sheer 
animal attack as in war to the more subtle conflicts or competi- 
tions of wit and cleverness; yet ever and anon the repressed 
animal form of the combative instinct comes to the surface and 
dominates behavior. Indeed we might proceed to trace in 
detail not only the place hostility assumes in social life, but 
also the places that the other instincts occupy, whether they 
be essentially social or not. We must turn, however, to an 
account of three forms of behavior that have a peculiarly 
significant position as socializing forces. 

Socializing Influences in the Individual. — 

1. Sympathy. — Sympathy is fellow-feeling. It is, when 
strictly defined, more than a mere cognitive appreciation of the 
emotions of another. To sympathize one must himself experi- 
ence the emotion of another to a greater or lesser degree. To 
sympathize with joy, anger, fear, and sorrow means that the 
observer himself is aware of similar emotions from perceiving 
them in others. The term sympathy, therefore, designates a 
certain relationship between the emotions of two or more indi- 
viduals, and does not refer to a particular feeling or emotion in 
one person. The relationship, accordingly, can occur only in a 
social situation. Its importance in the development of society 
has been stressed by Giddings (1905) in particular. It is 
important to note that sympathy not only depends upon a 
conscious interstimulation or social arousal, but it usually 
comes forth only when individuals of a kind are involved. The 
greater the similarity of the organisms the keener the sympathy. 



go GENERAL PSYCHOLOGY 

A man may project personality into his dog or his horse 
and share its feelings; but ordinarily sympathy is the 
stronger between man and man. Its greatest value lies in 
its function as a powerful cohesive factor among members of 
a group. 

Two forms of sympathy may be distinguished: passive 
sympathy, which gets no farther than the bare experiencing of 
similar emotions, and active sympathy, which, as Bain points 
out, leads its possessor to act out these emotions in behalf of 
another as though they were in reality his own. It is this latter 
form that is socially meritorious and adaptive. To see a neigh- 
bor in pain and distress is certain to arouse distressing emotion 
in the normal person. The passive type hurries on with averted 
face, or quickly turns to more pleasing topics in the paper, if 
the emotional situation has arisen from reading. Such an 
individual erects a defense mechanism of inattention and 
forgetfulness. The active type responds with aid if the situa- 
tion is painful, and with joyful acclaim if it is pleasant. The 
differences between the two are due in part to custom and 
convenience, and in part to the individual's innate organiza- 
tion by virtue of which he may be chiefly interested in self. 
Much passive sympathy exists from sheer lack of sufficient 
energy to meet actively all of the demands made upon one's 
fellow-feeling. 

Both forms of sympathy depend for arousal chiefly upon 
two factors: (i) one's experience in the past with such joys and 
sorrows as now demand sympathetic response; and (2) the 
consciousness that the individual to be sympathized with is a 
member of one's own kind. Both, therefore, wait upon one's 
power of imagination. (Imagination, let it be said, is here 
given its popular meaning.) It is difficult to sympathize fully 
with abject grief unless one has suffered it himself. The woes 
of poverty and the pangs of hunger can at best strike but a 
feeble response in the continuously prosperous and well-fed. 



SOCIAL AND RACIAL PSYCHOLOGY 91 

The influence of the second factor is equally clear and perhaps 
even more striking. Our inability to sympathize with some 
distant and unfamiliar group of people is largely due to our 
inability to appreciate clearly their similarity to ourselves. 
They are strange and unknown and we cannot well vividly 
portray their human characteristics, the deep human nature 
that makes the whole world of man akin. (There is, of course, 
the opposite fault which leads one to sentimentalize the convict 
and the international offender.) Our enemies, those hostile 
not only to me personally but to my clan, tribe, or group, those 
who are not for us, we explicitly place outside our "kind." Such 
limits as imagination sets to sympathy are both good and bad — ■ 
bad to the extent that worthy persons are excluded from the 
sphere of fellow-feeling, but good to the extent that they enable 
one to keep a hostile and uncompromising front to otherwise 
likable people who persist in violating international and social 
laws. Immediate face-to-face encounters with suffering indi- 
viduals act as so powerful a stimulant to sympathy that the 
aims of justice, which must be rational, are often deflected. A 
criminal or one who has broken custom and is cast out of the 
group is not only an offender; he is also a man and a former 
member of the group. The sympathy aroused by the stimulus 
of the latter fact may succeed in offsetting the non-sympathetic 
responses to his antisocial actions. 

The problem raised by the question of sympathy is essen- 
tially that of the place of emotion in social life. Emotions 
possess the great function of uniting by powerful associations 
the objects which are experienced with them. Two individuals 
(two persons, or a man and his dog) who pass through the same 
emotional situations are in the future bound together with 
"sympathetic" ties. They become, by virtue of that fact, 
henceforth members of a kind, of a clan, of a group. 

2. Imitation.- — Among sociologists Tarde and Baldwin in 
particular have stressed the influence exerted over the conduct 



92 GENERAL PSYCHOLOGY 

of the individual by imitation. In general to imitate is to 
duplicate the actions of another, as to sympathize is to dupli- 
cate the feelings of another. The child imitates its parents. 
One sparrow imitates another by flying when the other flies. 
The adult person imitates others in his conformity to fashions 
and conventions. It must be clear, therefore, that imitation 
may involve a greater or lesser degree of consciousness and 
a greater or a lesser amount of reasoning. There is no 
valid ground for assuming that imitation in animals involves 
rational processes. In a pack of wolves one animal sets up 
a howl and the rest chime in. In a flock of birds one flies 
and the rest follow. Terror in one member of a herd will 
stampede the entire group. These are the so-called cases of 
instinctive imitation, i.e., cases where one individual is said 
to be aroused to perform an act x by perceiving its occur- 
rence in another animal. These are the most primitive forms, 
the most widespread and automatic forms of imitation. 
There is no minimizing its importance in the preservation 
of the group through its effect upon team work and uni- 
formity of action. Cattle that did not stampede after their 
leaders would in time fail to survive. Social groups whose 
members did not act as other members act would disintegrate. 
This is all true, and yet there is little ground for the assumption 
of an instinct of imitation. Such a statement assumes that by 
heredity one or more instincts may be aroused not only by 
dangerous objects (fear), or by annoying objects (anger), but 
by the perception of the instinct itself as it occurs in another. 
Thus to speak of an "instinct of imitation" is to say that by 
heredity the awareness of fear in another arouses fear in the 
beholder, the awareness of anger itself arouses anger, etc. But 
the awareness of fear in another may arouse joy, shame, anger, 
or almost any other action in the beholder. The fact that fear 
is often contagious does not indicate that fear is itself the 
stimulus which brings about its spread throughout the group. 



SOCIAL AND RACIAL PSYCHOLOGY 93 

The keenest criticism of such a point of view we owe to Thorn- 
dike (1913). He writes: 1 

The spectators of an infuriated man, or of two men raging 
at each other, are not thereby provoked to similar acts and feel- 
ings. They manifest rather "curiosity- wonder," forming a ring 
to stare, the world over. So with other mammals. When Pro- 
fessor McDougall wrote that "anger provokes anger" he probably 
had in mind the fact that angry behavior of A toward B provokes 
angry behavior of B toward A. But that is irrelevant to his purpose, 
since he surely does not wish to contend that A's fleeing from B 
makes B flee from A, that A's shrinking from B makes B shrink from 
A, that A's self-abasement before B makes B abase himself before A. 

The whole difficulty lies in making sure in any particular 
case of imitation whether the similar responses are not due to 
the fact (1) that each animal concerned receives the stimulus 
that affected the first or imitated animal, or (2) that the imitated 
behavior itself contains a signal or stimulus for its repetition 
by others. So Thorndike continues: 2 

Under present conditions children would usually learn by training 
to run from what others ran from, to look at whatever others looked 
at, and the like, even if there were no original tendencies to do so. 
Moreover the object or event, the perception of which causes A to 
respond by a certain instinctive behavior which then spreads to B, 
is likely to be perceived by B also, so that whether his behavior is a 
response to A's behavior or to the object itself is often in doubt. For 
example, A's fear at a snake may arouse B's fear indirectly by merely 
calling B's attention to the snake. Finally A's response may, upon 
his perception of B, be modified to include certain behavior which 
acts as a special signal to provoke approach, fear, or whatever the 
response may be, in B. Thus the danger-signal might be given by A 
when frightened in company, though not when frightened alone; and 
B might respond, not to A's general fright, but to the danger signal. 

1 E. L. Thorndike. The Original Nature of Man (New York: 1913), 
p. 119. 

2 Ibid., p. 120. 



94 GENERAL PSYCHOLOGY 

We are unable to point out the exact mechanism by which 
all cases of imitation are brought about. In the chapter on 
" Animal Psychology" we had occasion to present a typical 
experiment upon rational imitation in monkeys. In this form 
of imitation the individual is supposed consciously to conform 
his actions to those of the imitatee. We indicated at that time 
that the monkey's behavior was understandable in terms of 
two factors, (a) the heightened interest due to the presence of a 
second member of the same species, and (b) the focusing of the 
animal's behavior, or attention, upon the essential features of 
the problem. The fact that man and many animals below 
man do act as they perceive others acting is beyond doubt. 
The reasons for this form of response will vary with different 
situations, as we have indicated in the quotation from Thorn- 
dike and in the discussion of animals. Perhaps the strongest 
reason for imitative activities in general lies in the sense of 
helplessness, loss, and fear that comes with the isolation from 
(non-conformity with) the group. Later in the discussion of 
custom we shall meet certain of the methods adopted by the 
group to compel conformity to, or imitation of, its ways. 

3. Suggestion. — 'Suggestion is the third factor upon which 
particular stress has been laid in explaining the social behavior 
of the individual. It is difficult and unnecessary to keep it 
separate and distinct from the imitative process. Ordinarily 
suggestion is defined as the process of uncritically accepting an 
idea that is encountered in social situations; but the line which 
separates that which is accepted and believed from that which 
is merely performed in common with others is exceedingly fine. 
Sympathy, imitation, and suggestion all refer to uniformities, 
to similarities among 'individuals of a kind. In all cases the 
arousal of the feeling, act, or idea in the second person proceeds 
in a manner practically automatic and unconscious. One hears 
the cry and is instantly sharing to some extent the sorrows of his 
neighbor. One sees his friend's new spring suit, and with little 



SOCIAL AND RACIAL PSYCHOLOGY 95 

or no deliberation procures one of the same style when it comes 
time to buy. One reads that his country has made a great 
contribution toward the winning of the war. "The wish is 
father to the thought," and the idea is uncritically welcomed 
with open arms. The similarity between the three processes 
is partly based upon the intimate connection between conscious- 
ness (or better, the neural activities accompanying it) and action. 
To sympathize is to feel as your neighbor does, but this involves 
no inconsiderable amount of similar responses or imitation. 
The same is true of suggestibility. It is but a short and fairly 
inconsequential step from belief in an idea to action in accord- 
ance with that idea. If the idea is shared by two or more 
individuals, the action will be shared likewise and is then termed 
imitation. 

We have already encountered the phenomena of suggestion 
in our study of abnormal psychology. Suggestibility is favored 
by any factors that tend to put the critical powers of the indi- 
vidual off guard and that permit an idea to obtrude itself into 
consciousness with little or no critical consideration. Resist- 
ance to suggestion goes along with a wide and highly organized 
experience. As a result, women, children, and members of the 
more primitive races are in general more open to suggestion, 
to the uncritical acceptance of ideas, than are men, adults, and 
the more cultivated races. We may follow Ross, in the main, 
in listing the factors that aid suggestion : prestige, age, race, sex, 
emotional excitement, repeated stimulation, and the feeling of 
being but one person out of many. By prestige we refer to the 
effect of authority in securing the unresisting acceptance of an 
idea. Let a high critic of art pronounce a picture poor, and 
immediately for many the picture is no longer artistic. Let 
custom through some of its representatives say that such and 
such conduct is wrong and the edict is unquestioningly accepted 
by most people. I write an account of suggestion, and the 
students more or less uncritically accept it as true because as a 



96 GENERAL PSYCHOLOGY 

writer of books I have prestige and authority 1 This factor is 
a valuable and unavoidable aid in the dissemination of ideas 
among a group of people, the chief safeguard, however, being 
that the prestige emanate from ability. In many cases prestige 
depends upon the age, race, or sex of the leader; thus we may 
group these factors as subordinate ones under the main one of 
authority. Insistent, insidious repetition will also break down 
and overcome resistance and cause ideas to be accepted as 
correct. Familiarity breeds acquiescence. The effects of the 
other two factors, emotion and numbers, we may best illustrate 
under the topic of mob action to be discussed below. 

The Nature of the Self. — Under the present topic we shall 
consider the self only as it appears in consciousness. In a very 
true sense the self is identical with the individual organism. 
From this point of view an account of the self would involve a 
discussion of all its characteristics as an individual apart from, 
though related to, other individuals. Psychology as a whole 
is the study of the individual's consciousness and behavior. 
Consequently, the entire account of the present book is directed 
•toward drawing the outlines of the individual in so far as he 
may be subject to psychological analysis. The present section, 
however, deals only with a very limited part of the topic, viz., 
the nature of self -consciousness. In our discussion we shall 
follow along the road mapped out by James. 

I am, it is true, a part of all that I have met. But within 
my total consciousness there are certain elements that are more 
intimately and peculiarly "me" than others. My body is 
probably first. It is represented in consciousness funda- 
mentally as sensations from the muscles, skin, and viscera. 
These sensations persist from moment to moment and form a 
major portion of the consciousness of continued bodily existence. 
Organized in this manner and supplemented by memories of 
the past, they may be termed the bodily-self. There is also 
a self-as-others-know-me which includes my awareness of 



SOCIAL AND RACIAL PSYCHOLOGY 97 

myself as I think others believe me to be. It may be quite 
different from my self-as-I-know-myself. Then there is the 
club-self, the religious-self, and in fact a self for each of the 
fundamental situations of life which I have been accustomed 
to meet. James states the situation as follows: 1 

In its widest possible sense, however, a man's self is the sum total 
of all that he can call his, not only his body and his psychic powers, 
but his clothes and his house, his wife and children, his ancestors and 
friends, his reputation and works, his lands, and horses, and yacht, 

and bank account Its own body, then, first of all, its friends 

next, and finally its spiritual dispositions, must be the supremely inter- 
esting objects for each human mind. 

Each of these fairly numerous selves has a certain distinct- 
ness and individuality. Each is an organized unit dominated 
first by the standards of conduct applicable to the specific 
situation, and second by the awareness or consciousness of 
itself as in that situation. Ordinarily and normally all of these 
selves are so closely interrelated that they are felt as one. 
Yet when my club-self is dominant I tend to forget and ignore 
what I am as a professor-self and vice versa. So the week-day- 
self forgets or ignores the Sunday-self. These forgettings are 
defense mechanisms erected by the dominant self to save it 
from self-criticism or from other inconvenience. Ordinarily 
the amnesia (forgetting) is not so complete as to be termed 
pathological. Occasionally, however, it may be so, as we have 
seen. Then we have the cases of multiple personality, i.e., 
extreme splits in a normally slightly divided self. Freud has 
taught us to hold that the exaggeration in the amount of divi- 
sion is due to a relatively strong need for a defense mechanism. 

The Development of the Self. — Each of the selves that we 
have so briefly mentioned is changing from the time of its 
initial inception to its final death. This change may be either 

1 William James. Principles of Psychology (New York: 1890), I, 
291, 323- 



98 GENERAL PSYCHOLOGY 

a growth or a decay. Perhaps few of the average individual's 
many selves continue their existence until the time of his 
bodily death — in fact the bodily-self is the only one that usually 
does so. The content of this self — interest in the welfare of the 
body as represented largely through kinaesthetic, cutaneous, 
and organic sensations — as a rule changes but little. As opposed 
to this instance the contents of one's social selves are in constant 
flux. The child's family increases, decreases, and varies in its 
many fortunes. Likewise does one's family as a man. The 
circle of one's friends and acquaintances is now large, now small, 
now intellectual, now plodding. With the average individual 
(at least in the cities) this fluctuation in content is incessant. 
It is more difficult to generalize in the case of that social self 
termed the religious. Many individuals find this content stable 
and unvariable. Others are tossed about for most of their 
lives upon the thorny beds of religious unrest, repudiating first 
this and then that content, refusing to be an orthodox self, 
rebelling at an unorthodox self, and perhaps never reaching a 
decision. This religious-self after its first appearance in early 
childhood persists throughout the greater part of the physical 
lifetime of the individual. Undoubtedly few if any normal 
human beings exist after childhood who do not place them- 
selves in relation to a power greater than themselves. The 
content of such a religious-self will vary widely, depending upon 
whether the individual conceives this Greater Power as Abso- 
lute, as only superhuman, as spiritual or material, as solicitous 
or indifferent, as good or evil, etc. The content of this self 
will include all of one's behavior and standards governing that 
behavior so far as it involves a relation to this Power greater 
than the self. It should now be stated in amplification of our 
foregoing comments upon the bodily-self that, although normally 
it is the most persistent and lasting self, instances do at times 
arise where it is totally repudiated in the interests of a social 
self. Asceticism is the attitude which dominates when the 



SOCIAL AND RACIAL PSYCHOLOGY 99 

bodily-self is denied and destroyed so far as consciousness is 
concerned. Extreme cases are on record where apparently 
hardly a vestige of interest and concern for the bodily-self 
remains. The social self which thus more or less totally excludes 
any other may be a religious one or it may be a devotion to the 
more secular ideals of justice and fair play. The successful 
growth of any of one's selves involves the adjustment to or 
ehmination of its other competing selves. 

What we have just written can be best illustrated from 
James: 1 

I am often confronted by the necessity of standing by one of my 
empirical selves and relinquishing the rest. Not that I would not, 
if I could, be both handsome and fat and well dressed, and a great 
athlete, and make a million a year, be a wit, a bon-vivant, and a lady- 
killer, as well as a philosopher; a philanthropist, statesman, warrior, 
and African explorer, as well as a "tone-poet" and saint. But the 
thing is simply impossible. The millionaire's work would run counter 
to the saint's; the bon-vivant and the philanthropist would trip each 
other up; the philosopher and the lady-killer could not well keep 
house in the same tenement of clay. Such different characters may 
conceivably at the outset of life be alike possible to a man. But to 
make any one of them actual, the rest must more or less be suppressed. 

These competitions between the selves of a given individual 
contain the great dangers of mental maladjustments as well 
as the possibilities of spiritual growth. Social conditions, as 
we have seen, require the repression of certain possible selves. 
Too often this has meant an attempt to distort essential human 
nature. In those who fail to work out a modus vivendi, who are 
unable to adjust their impulses to social demands without doing 
themselves violence, mental disease appears. They become the 
neurotic, the hysterical, the obsessed. 

Baldwin on the Growth of the Self. — So far, in our sketch of 
the development of the self, account has been taken only of the 

1 William James. Op. cit., I, 309-10, 



ioo GENERAL PSYCHOLOGY 

variations of content in the various selves. Baldwin has 
described in addition certain phases that each self passes through 
in its attitude, particularly, toward the corresponding selves 
of other individuals. 1 Not only will my club-self vary in its 
content from time to time so long as it exists, but it will take 
certain attitudes toward the club-selves of others. Two atti- 
tudes of chief importance are to be distinguished, which Baldwin 
calls the subjective and the ejective selves. The subjective self 
is the self as submissive, as imitative — a learning self. As 
ejective the self is aggressive and masterful, putting into practice 
that which it has learned as subjective. I enter a strange club. 
Its ways and customs as embodied in the club-selves of its 
members, the standards by which it governs conduct, are all 
as yet unknown to me. As a new environment in which I am 
to move, it has prestige. I am thrown into a submissive atti- 
tude. I observe. I move respectfully. I note and learn. 
Then having mastered the new situation, having expanded my 
club-self to take in its new surroundings, I change my attitude 
from that of a novice to that of a habitue. My manner becomes 
easy and masterful. I unconsciously read over into the club- 
selves of my fellow-members the pleasures and motives that I 
now find within myself. I now "eject" that which has hitherto 
been subjective. One may follow through in a similar fashion 
subjective and ejective attitudes of the many selves in a thou- 
sand and one situations. We cannot here discuss, but it is 
interesting to note, the fact that the submissive self is dominated 
by a mild emotion of fear and the ejective, or aggressive, self by 
a mild anger. Selfhood and also fear and anger are essential to 
each individual. 

B. SOCIAL INSTITUTIONS 

Introduction. — By a social institution we shall mean any 
of the more or less stable and permanent relationships 

1 We shall here rather use Baldwin's contribution than attempt to 
give an exposition of it. The present account therefore varies considerably 
from the original. 



SOCIAL AND RACIAL PSYCHOLOGY 101 

entered into by individuals. Society itself is a social institu- 
tion. We mentioned others at the beginning of our present 
chapter: fashions, conventions, traditions, the mob, the crowd, 
the public, religion, morals, law, language, art, etc. It should 
be clear that only part of the individual is involved in each insti- 
tution. One self will be found particularly emphasized in 
fashions, another in morals, another in religion. It would far 
exceed the scope of our present bird's-eye view of the field of 
social psychology to discuss many of these topics in detail, for 
each in turn calls not only for an analysis of structure, but also 
for a survey of the factors causing constant changes in this 
structure. Accordingly we shall limit our present account to 
brief comments upon the nature of custom and the mob. 

The Nature of Custom. — Customs are uniform modes of 
acting that are transmitted by social heredity from generation 
to generation. Thus one finds religious, moral, commercial, 
legislative, and other customs. They differ from ordinary 
habits in that their age extends back of the present generation 
and in that they are habits common to a large number of indi- 
viduals. Like habits (see the discussion below, p. 176) they 
arise partly by chance and partly as a result of reflection. 
Perhaps in each case both factors are active, varying only in 
relative amount. Particularly in primitive customs does chance 
play a dominant role. Let us describe a hypothetical but 
typical case of custom-formation in hunting, remembering that 
the securing of food is a matter of tremendous importance in 
primitive life; that strong emotions are involved; and that as 
a matter of life and death the savage can afford to ignore no 
power that may aid him. On the morning of the hunt he comes 
from his shelter with his bow and arrows and stumbles. The 
day proves unfruitful. Stumbling becomes an omen of bad 
luck, a thing to be eliminated from the procedure of hunting. 
In like manner the full moon may also become associated with 
poor hunting, and the custom be confined largely to the dark 



102 GENERAL PSYCHOLOGY 

of the moon. If failure attends the hunting for several days 
and then gives place to success shortly after the hunter has 
rubbed the bow three times and said to himself, a O arrow, shoot 
straight," this practice becomes incorporated into the hunting 
procedure, is taught to the hunter's friends and children, and 
finally becomes a well-established custom. As growth occurs, 
some customs are cast off and their adherents are termed non- 
believers. Present-day society is replete with such vestigial 
modes of acting. "Do not plant potatoes in the dark of the 
moon." "Do not pass a pin without picking it up." "Thirteen 
is unlucky." These useless and more or less rejected customs 
rest upon a defective analysis of the relation of cause and effect 
in nature. The reason why the above injunction about potatoes 
does not influence most of us is that we can detect no causal 
relationship between growing potatoes and the phases of the 
moon. In a like manner the superstitions concerning the num- 
ber 13, the spilling of salt, and many other acts and their sup- 
posed significance do not generally affect us. Among the more 
intelligent classes the tendency is to form all essential customs 
upon the result of reflection. For this reason laws are drawn 
up by deliberative assemblies. Rules of planting and reaping 
are devised at the agricultural colleges. Yet even with the 
most intelligent a fairly large field of behavior remains under 
the reign of chance impression, partly because — as with the 
number 13 — the situations are not vital for the individual, and 
partly because some customs, such as religion, the control of 
sex behavior, the right of property, involve such tremendous 
issues that society fears to tamper with accepted custom lest 
great evil result. 

What are the factors that give custom its grip on the indi- 
vidual's various selves? They may be listed as follows: (1) fear 
of the unknown and the unusual that are to be found just out- 
side of the customary mode of action; (2) the ease, convenience, 
and lack of fatigue in doing the accepted; (3) the prestige of 



SOCIAL AND RACIAL PSYCHOLOGY 103 

the old; (4) the effect of public opinion. The more important 
the custom to the individuals concerned the greater is the 
influence of the first factor. The primitive man will not depart 
from his hunting custom or from his method of caring for his 
cattle, because to do so is to leave a successful form of response 
for untried possibilities with suffering and death the penalty of 
failure. Present-day peoples are loath to depart from the 
customary marriage regulations for much the same reason. It 
is to run the risk in this very important social problem of "jump- 
ing from the frying-pan into the fire." And then, too, in all of 
these cases it is much easier to act than to think. The path 
of the reformer is always hard and seldom attractive. The 
prestige of the old is the prestige of that which has worked well 
enough at least for survival. As a group, China with its 
ancestor-worship is perhaps the most striking illustration of 
this factor. Public opinion has its effect upon the individual 
partly through the great prestige and suggestive power that 
attach to large numbers and partly through the fear of ostracism 
and isolation that result from non-customary behavior. 

The Mob. — Customs are relatively permanent social institu- 
tions. Mobs are very transient. Many selves may exist and 
never take part in social relations that even closely approxi- 
mate mobs, while no self avoids custom. In a mob we have 
essentially a congregation of individuals dominated emotionally 
and intellectually by a certain situation. The particular self 
involved will depend upon whether the situation concerns the 
family, religion, or the club, for example. Suggestion and 
sympathetically aroused emotion are the great forces at work. 

We may describe the nature of the mob in the following 
schematic manner: (1) The exciting cause, a murder, let us say, 
stirs the community deeply. Consciousness focuses itself 
definitely upon the details and upon the identity of the probable 
offender. (2) The news is spread that the offender has been 
captured and that the people are gathering in the town square. 



104 GENERAL PSYCHOLOGY 

This leads to a further increase of the crowd which at this stage 
is governed largely by curiosity. (3) In such a group sug- 
gestibility is at its height, due to the emotional status of each 
individual. The way is prepared for irrational mob action. 
(4) A leader appears and harangues the crowd. He fixes their 
attention further upon the details of the crime, arouses their 
emotions by playing upon custom violation and the need of 
awful punishment. Then with the group in a state of high 
tension, the leader, or some member of the group who thus 
becomes a spontaneous leader, shouts a demand for hanging 
the guilty one. (5) The suggestion catches and spreads. To 
have the idea is to act upon it. 

In this schematic way we might follow the further irrational, 
suggestible, childish behavior of the group dominated in this 
manner by a single emotional idea, but the situation is too 
familiar to require more description. The case is essentially 
one of group hypnotism. One may draw similar illustrations 
from the fields of political conventions, religious revivals, etc., 
which reveal the same frailties of the individual in a crowd. 
Indeed never a year passes but one can find excellent descriptions 
in the newspapers of mob activities. In so far as they take the 
form of killing a victim, so far are they examples of the blind 
primitive animal-anger whose purpose is the annihilation of the 
opponent. In each mob situation an emotion of some kind is 
the dominant influence making for social unity. 

Other institutions of society we must leave untouched and 
proceed to an even briefer sketch of racial psychology. 

II. RACIAL PSYCHOLOGY 

Racial psychology concerns itself with differences between 
races in behavior and consciousness. To what extent do the 
customs and other activities of races differ, and what are the 
contributing causes? To what extent do the conscious experi- 
ences of races differ, and why do they do so? What are the 



SOCIAL AND RACIAL PSYCHOLOGY 105 

relative abilities of different races when examined by the method 
of mental tests, or by a comparison of their respective institu- 
tions? The question in all of these problems is, "How will 
individuals vary in their different characteristics by virtue of 
their membership in different racial stocks?" These questions 
indicate clearly that the topic of racial psychology is related very 
intimately to anthropology and ethnology. Most of its facts 
and theories are, up to the present time, the fruits of investi- 
gators who are not primarily psychologists. The situation is 
in process of fairly rapid change now to the extent that mental 
tests are being applied, and in the future one may expect accu- 
mulations of facts bearing upon relative intelligence that have 
been subjected to the most rigid scientific standards. The most 
extensive data of a reliable nature at the present time consist: 
(1) of descriptions of the customs of different races with some 
suggestion of their geographical, economic, and social causes; 
and (2) of physical (anthropometric) measurements showing 
particularly differences in skull capacity and form. The great 
and fascinating field of primitive custom and culture we shall 
pass over, though in the preceding account of social psychology 
we have described a few of the factors underlying their formation 
and preservation. The topic here to be presented for the 
purpose of illustrating the concrete problems of racial psychology 
is that of racial differences in general ability. 

Racial Differences in General Ability. — The general ques- 
tion of inferior races is not whether or not there are inequalities 
in racial attainments, for there is ample evidence that all are 
not favored sons. The essential problem is whether or not there 
are inherent differences in ability. The question we are raising 
is psychological and not ethical. Cannibalism, polygamy, and 
ancestor-worship may be thought to be inferior in moral worth 
to the corresponding practices of Europeans; yet it does not 
follow that the adherents of these customs are mentally inferior. 
They may be able to see, hear, smell, and taste as acutely as 



106 GENERAL PSYCHOLOGY 

we, and their powers of thinking may be of a high grade. On 
the other hand peoples, races, may share the same customs and 
culture and yet differ more or less in intelligence. There has 
been a very strong tendency to treat all racial stocks as inferior 
to the European partly because the present European has 
assimilated and outdistanced more primitive races, and partly 
because today the "lower races," i.e., Africans, Australians, 
American Indians, and others, vanish and fade before his 
advance. Boas (1901, 191 1) and other anthropologists do well, 
therefore, when they point out social, economic, and physio- 
logical reasons for race predominance. Modern occidental 
contact with more primitive races no longer is one of assimila- 
tion and intermingling, but largely one of exploitation. Roman 
culture conquered its barbarous captors in the final end of the 
empire, but prior to that the Romans had mingled more or less 
freely with their colonials. The Mohammedans absorb the 
native peoples that are below them, while the Caucasians do 
so almost not at all. At the present diseases of civilization, 
e.g., venereal diseases and tuberculosis, attack the newly found 
races more than was apparently the case in earlier racial con- 
tacts and thus aid racial differences in survival. In evaluating 
the great spread of occidental control over the world, note should 
be taken that relatively high civilizations (e.g., those of the 
Aztecs and Incas) have existed among races now extinct. 
Granted that these races were 4,000 years behind in culture, 
yet when one considers this in comparison with the age of man, 
Boas points out that accidental causes and not mental inferi- 
ority may well explain the facts. 

It has long been urged that many of the primitive races 
reveal their mental inferiority in their language. One mark of 
intelligence is the ability to detect sameness or identity in widely 
differing objects. This is the capacity for acquiring workable 
concepts or general notions. Primitive races, it has been said, 
make too many irrelevant distinctions. They may call a small 



SOCIAL AND RACIAL PSYCHOLOGY 107 

nut one thing and a large nut another, and yet may have no 
word for both. They are unable apparently to see that while 
the nuts are different yet nevertheless they are both nuts and 
very similar. Or again words will exist for many kinds of 
horses according to color, and yet there will be no general word 
for horse. In other words, so the criticism goes, primitive 
races have more words than ideas. It is this general point of 
view that Hocart (191 2) criticizes most brilliantly, pointing out 
that a language must be judged not in terms of dictionaries 
but in terms of its suitability to a particular environment. The 
reason why one race will make many distinctions with certain 
objects and relatively few with others is because the former 
objects have many specific uses and the latter few. Let us 
illustrate by a quotation from Hocart: 1 

The Solomon Islands possess a most useful nut, the kanary, 
which engrosses much of the islanders' interests and fills much of their 
existence. In those parts investigated by Dr. Rivers and myself 
they distinguished two kinds: the vino and the ngari; in our eyes 
it was merely a difference in size, and we might never have considered 
them otherwise than as large and small specimens had not the natives 
given us the two words. Yet closely related as they are, they have 
no common term. Had we proceeded no further, we might have 
ascribed this deficiency to an "incapacity for clearly apprehending 
identity in difference." But is it reasonable to suppose that an 
identity so glaring could not peep through the thin veil of differences ? 
.... We found that from trifling differences sprang a host of 
momentous ones — technical, commercial, and religious: the seasons 
of the two do not coincide; they are gathered differently, because 
the branches of the vino will bear a man and the ngari will not ; they 
are cracked differently; .... they are preserved differently; 
.... the two, in fact, are only identical in the kitchen, and therefore 
they have but one word for the roasted kernels and puddings of 
either. 

1 A. M. Hocart. "The Psychological Interpretation of Language," 
British Journal of Psychology, V (1912), 272, 275. 



108 GENERAL PSYCHOLOGY 

Again an illustration from the Fijian language will show the 
opposite side of the matter. Where the group takes no interest 
in certain objects, there it makes no fine distinctions — not 
because it lacks the mental ability, but because such distinctions 
would be useless in its social existence. In English — ■ 

a cock crows, a hen cackles, a pigeon coos, a jackdaw caws, other 
birds sing or chirp or warble, but they cannot cry as they all do in 
Fijian. Is Fijian therefore more advanced in ornithology ? On the 
contrary, it is because they take no interest in birds that they have 
but one word 

So one might continue citing peculiar cases in different 
languages where ideas that we might regard as necessary are 
lacking and unnecessary ones are present. But one really need 
not go outside the English language. Every special field has 
its particular vocabulary. Experts in most fields regard those 
who cannot use their jargon as more or less inferior beings! 
The farmer, the horseman, the mechanic, the psychologist, all 
find it necessary to draw certain distinctions and to omit others. 
To most of us horses are all of a kind, and one rock is much like 
another. But the specialist speaks of mares and stallions, and 
of chalks and limestones and shale. Some environments make 
greater demands on their inhabitants than others and therefore 
stimulate various accomplishments, although the peoples con- 
cerned may be of equal ability. There is no question but that 
all men imagine, remember, think, and feel. All can see, hear, 
smell. There is little reason to believe that savages have more 
acute senses than civilized man. It is true that they hear 
slight sounds and see faint trails that escape the townsman; 
but he too can see and hear them if he will practice and be 
interested. 

The chief differences between European stocks and the 
so-called inferior races will undoubtedly be found in general 
intelligence as revealed by mental tests of the kind described 
in the chapter on "Individual Psychology." Very significant 



SOCIAL AND RACIAL PSYCHOLOGY 109 

beginnings have already been made with particular reference 
to a comparison of whites and negroes in this country. This 
work, carried on by Mayo, Baldwin, Pyle, Ferguson, and others, 
including the army psychologists, indicates a significant superi- 
ority of the white over the black in general intelligence, i.e., in 
learning capacity, or ability to adjust to novel situations. 
Although the topic is of absorbing interest, it must be passed 
by without further comment, as must also such other essential 
problems of racial psychology as emotional control, morality, 
intermarriage, and birth- and death-rates. 

Resume of Part I. — Psychology, it will be remembered, 
is a science of human nature. And the purpose constantly 
before it is to understand just what a human individual is with 
particular reference to his behavior and consciousness. To 
gain this understanding one must consider what characteristics 
in this respect man has by virtue: (1) of his relationship to 
infrahuman animals; (2) of his relative ranking in ability in 
his particular population; (3) of the abnormalities that he is 
prone to share or to develop; and (4) of his membership in a 
certain society and a certain race. We have now completed a 
survey of these fields. It remains in Part II, "Normal Human 
Adult Psychology," to characterize man from the standpoint 
of those forms of behavior and consciousness which all men 
possess in a degree dependent upon the influence of those factors 
which we have just outlined. 

REFERENCES 

Ames, E. S. The Psychology of Religious Experience. Boston: 1910. 
Baldwin, J. M. Mental Development in the Child and in the Race. 

New York: 1895. 

. Social and Ethical Interpretations. New York: 1897. 

Bentley, I. M., Clark, Helen, and Woolbert, C. H. "Studies in 

Social Psychology," Psych. Rev. Mon., XXI (1916), No. 4. 
Boas, F. The Mind of Primitive Man. New York: 191 1. 



no GENERAL PSYCHOLOGY 

Ellwood, C. A. Introduction to Social Psychology. New York: 191 7. 
Ferguson, Jr., G. 0. "The Psychology of the Negro," Archives of 

Psychology, XXV (1916), No. 36. 
Hocart, A. M. The "Psychological Interpretation of Language," 

British Journal of Psychology, V (191 2), 267-80. 
Leuba, J. H. A Psychological Study of Religion. New York: 191 2. 
McDougall, William. An Introduction to Social Psychology. Fourth 

edition. Boston: 191 1. 
Mayo, M. J. "The Mental Capacity of the American Negro," 

Archives of Psychology (1913), No. 34. 
Ross, E. A. Social Psychology. New York: 1908. 
Tarde, G. The Laws of Imitation. Trans, by Parsons. New York: 

1903. 
Thorndike, E. L. The Original Nature of Man. New York: 1913. 
Woodworth, R. S. "Racial Differences in Mental Traits," Science, 

N.S., XXXI (1910), 171-86. 
Wundt, William. Elements of Folk Psychology. Trans, by Schaub. 

New York: 1916. 



PART II. NORMAL HUMAN ADULT 
PSYCHOLOGY 



CHAPTER I 

ATTENTION 

Attention and Selection. — In a general way everyone is 
familiar with the fact of attention. At one moment I attend 
to tennis, at another to eating, and at a later moment I con- 
centrate upon psychology. Each time I am absorbed in pursuit 
of the particular event I have chosen. I glance over the land- 
scape and note, not all details at once, but first the blueness of 
the sky, then the trees and their colors, a bit of a house here, and 
a rolling pasture there. It is said that my attention is moving 
over the scene before me. In order to understand, in order to 
learn and remember, I must attend to certain matters and not 
to others. I must select them and hold them in the focus of 
consciousness. The technical description of attention will 
vary with the angle of approach as follows: From the struc- 
turalistic point of view attention is not an activity but a char- 
acteristic of consciousness — its varying degrees of clearness. 
Those thoughts, objects, and emotions, indicated in our preced- 
ing illustrations, to which we attend become clearest, stand out 
above the other conscious contents of the moment in distinct- 
ness. From the objective or behavioristic point of view it 
would be said that that stimulus which controls the dominant 
activity of the moment is in the focus or center of attention. 
So a dog "attends to" his food when reaction to food is the 
dominant activity of the moment. From the point of view of 
activity or function, attention is often said to be the selective 
activity of consciousness. We voluntarily attend to this as 
opposed to that, i.e., we select the one and not the other. Atten- 
tion, however, is not a directing agent or force which throws a 
greater or lesser degree of light upon an object as a man casts a 

IT 3 



114 GENERAL PSYCHOLOGY 

spotlight here and there. Attention is the clearness into and 
out qf which objects move. As such it is coextensive with con- 
sciousness, although not all states of consciousness possess it 
in equal degree. Accordingly, there is really no such thing as 
inattention. Inattention to one thing means attention to 
another. Whether an object or content shall enter consciousness, 
and whether it shall be in the focus of attention, are deter- 
mined by selective agencies other than attention and conscious- 
ness itself. Neither of these determines whether I shall hear 
a tone which is sounded or whether I shall pass it by. Neither 
can decide whether I shall notice the war news or the editorials, 
and it is beyond the power of either to select out and make me 
immediately aware of infra-red rays of light or of air vibrations 
above 50,000 per second. The conditions of selection lie in the 
organism and are partly a matter of the nervous system. Any 
other answer assumes that consciousness acts upon the body, a 
point of view which we cannot accept. 

Selective Agencies. — Here at the beginning of our account 
of selective agencies the general rule may be laid down that 
those states of consciousness are clearest whose neural accom- 
paniments are most active, i.e., stand in the focus of neural 
(cortical) activity at the moment. What neural processes shall 
occupy this position at any one moment will depend, further- 
more, upon other neural conditions. A very loud noise attracts 
our attention at once, only by virtue of the fact, however, that 
instinctive or hereditary connections in the nervous system 
seem to facilitate the nervous processes aroused by such a noise. 
These statements will become clearer if we take up in a serial 
order the so-called conditions of attention. It will then be 
seen that the subjective conditions are the fundamental deter- 
miners of what shall enter the focus of consciousness. 

Anatomical Conditions. — The conditions (selective agencies) 
which determine what state of consciousness shall enter the 
focus of attention are: anatomical, objective, and subjective. 



ATTENTION 115 

The anatomical conditions are the limitations imposed upon con- 
sciousness — or upon neural activity — by the number and char- 
acter of the sense-organs. Of all the transformations and 
transfers of energy that go on in the universe, only certain ones 
are reacted to by man and animals. At any one moment of 
time each organism is bombarded by innumerable stimuli. 
Ether- waves and air- waves of all ranges of frequency, pulls of 
gravity, changes in electric potential, etc., are the forces in 
question which may vary from moment to moment. It is 
these forces which constitute the environment in which the 
animal lives. The very conception of an organism's adjusting 
itself to its environment presupposes selection. At one moment 
it will react to light, at another to sound, and then to odor. 
This phase of its adjustment is absolutely determined by the 
number and nature of the sense-organs that the animal possesses. 
Sense-organs, as we shall see later, are merely points on the 
organism which are particularly sensitive to certain forms of 
energy. That we do not have more of them and different ones 
must be due to the fact that the sense-organs we have serve to 
select out or adjust us to those forms of energy which favor 
survival, which enable us to detect food and mates, and which 
aid us in determining locations that are injurious (painful), 
that are too cold or too hot, etc. 

Objective Conditions. — Objective conditions are those 
characteristics of physical (external) objects and events by 
virtue of which these phenomena either (1) force themselves 
upon our attention, or (2) lend themselves most readily to atten- 
tive observation. The first condition covers many everyday 
facts. Intense sounds, bright lights, strong odors, tastes, and 
contacts, all tend to crowd themselves into the focus of attention. 
The same is true of moving things. Animals that feign dead 
escape notice, while a mouse that moves catches the cat's eye. 
Throughout the animal scale movement or change in the 
environment is irresistibly attended to. The movement need 



n6 GENERAL PSYCHOLOGY 

not be visual. The notes that make up the melody of a song 
rise and fall in pitch. In this manner they change in relation 
to the accompaniment, and accordingly make the melody easily 
attended to or followed. The skin is more sensitive to move- 
ment than to the discreteness or separateness of stimuli. One 
can place the two points of a compass so close together on the 
skin of the forearm that they are sensed not as two but as one. 
Suppose that this distance is i cm. If now one of the points 
is moved over a distance of \ cm., distinct movement will be 
felt. A similar phenomenon occurs in peripheral vision, i.e., 
in the field of vision away from the immediate object upon 
which one's eyes are focused. If one holds his open hand far 
enough toward the periphery of vision so that it can be seen only 
as a blur, it will be noticed that, although the individual fingers 
cannot be seen, movement of any one of them can be clearly 
apprehended. This is confirmed by careful experimentation 
which indicates that the threshold for movement is lower than 
the threshold for discrete objects. The adaptive value of these 
facts for the organism is very clear, for moving things are likely 
to be either food, mates, or enemies. It is very probable that 
stimuli of great intensity, loud noises, bright lights, etc., get 
into the focus of consciousness as much by virtue of the fact 
that they are changes from preceding noises and lights as by 
the fact of their intensity. Movement is the fundamental objec- 
tive condition of attention. 

In addition to those characteristics of objects by virtue of 
which we feel forced to attend to them, there are other character- 
istics which enable us to attend accurately — the second objec- 
tive condition which we mentioned above. These conditions 
have been carefully studied in the psychology of testimony. 
The problem is to determine the objective factors which con- 
dition not so much our attention to the presence or absence of a 
noise or other happening as our attention to the details of the 
event. Attention, as we have seen, is essentially selection and 



ATTENTION 117 

discrimination on the conscious side. What objective factors 
favor the discrimination of parts within a given total event? 
First, the object must not be presented for too brief an interval of 
time, for opportunity must be afforded for the organism to adjust 
itself to the new situation. Second, the objects must not suc- 
ceed each other so rapidly that they tend to fuse or mix together. 
Exactly how much time shall be given will depend upon the com- 
plexity of the object and the amount of detail to be discrimi- 
nated. We shall have occasion to describe data bearing upon 
this point later under, the discussion of the scope of attention. 
Subjective Conditions. — Under the caption "subjective 
conditions" of attention we may list the following: instincts, 
habits, and the laws of association. The first two conditions 
rest upon the third — the fact that if two states of consciousness 
(or two forms of behavior) have been experienced together, when 
one reappears the other tends to follow. This we may term 
the fundamental law of association. Instincts are inherited 
associations, and they represent original, innate modifications 
of the nervous system by virtue of which nervous impulses 
flow over one system of pathways rather than over another. 
A loud noise occurs. It attracts my attention by virtue of the 
fact that it is a sign of possible danger and therefore a stimulus 
for the instinct of fear. We are by heredity attentive to objects 
connected with food, sex, rivalry, play, curiosity, anger, fear, 
jealousy, and the whole remaining gamut of instincts. If 
organisms existed devoid of the anger instinct, threats against 
life and property would not attract attention unless they were 
also connected with fear. Individuals in whom jealousy is 
dormant do not attend to certain events which are frequent 
stimuli for that instinct. The fundamental motives and 
interests are furnished by the instincts. This is inevitable, 
for they represent the solutions which have been found advan- 
tageous in the history of the race for certain important difficult 
situations, dangers, and other problems of primary importance. 



u8 GENERAL PSYCHOLOGY 

■* 
The term habit covers customs, peculiarities of education, 
and individual idiosyncrasies. Habits are built up by the indi- 
vidual with the inherited forms of action as a basis. They 
serve to limit further the lines of action taken by the organism, 
to fix more definitely the objects in which he as an individual is 
interested, even as the instincts set the limits of his interest as 
a member of a given species. Where the habits are passed from 
one generation to another by training, we speak of custom and 
tradition. It is a familiar fact that customary and traditional 
manners and beliefs are the things we hear and see, are the objects 
to which we attend. This is so to the extent that our behavior 
and consciousness follow the socially accepted (selected) pattern. 
A carpenter starts to build a house or a cobbler to mend a pair 
of shoes. Each attends to first this object, then that, and then 
the other, because that is the traditional way to build the house 
or to mend the shoes. A Chinaman's attention is attracted 
to the conservative phases of action and to the avoidance of 
outsiders, because this is a customary mode of behavior in these 
matters. Perhaps language is the greatest custom of all. This 
"idol of the tribe," as Bacon would say, fastens itself on all men 
to some degree, for little comes into the focus of attention that is 
not named. A faulty vocabulary notoriously limits our thoughts 
and curtails the things to which we attend. In addition to these 
habits shared with other members of the social groups, there 
are those which arise peculiar to the individual or to the small 
group. These are the hobbies and professions of men. Objects 
to which we attend as psychologists are overlooked by others 
and even by ourselves when we are masquerading as laymen. 
The objects constituting an athlete's world are quite diverse from 
those making up the environment of a judge, and these differ 
much from those of other professions. A geologist sees things 
that escape the eyes of ordinary mortals, and so the story goes. 
Each habit acquired determines new interests in terms of which 
objects will be selected and will enter the focus of consciousness. 



ATTENTION 119 

We turn now to a brief statement of the part played by the 
laws of association in conditioning attention. The basic 
principle has already been stated — the fact that, if two states of 
consciousness have been experienced together, when one of 
them again enters consciousness the other tends to follow. 
These laws are not forces mental or physical, but are formula- 
tions of relationships detected between successive states of 
consciousness and between their parallel neural processes. If 
at one moment the letter a is in the focus of my consciousness, 
b tends to follow. This may be due to the frequency or the 
vividness of the association between the two. It may be because 
b arouses the same emotion that accompanies a; for it is a 
familiar fact that when I am gloomy, gloomy thoughts crowd 
in upon me, and when I am in a joyful mood only the 
pleasant things get audience. The selection of what I shall 
attend to is begun by the structure and functions of my sense- 
organs, is further completed by instinct and habit, and is then 
finished by the influence of the states of consciousness (neural 
activities) that have occupied the focus of consciousness the 
moment before. The action of each of these factors is condi- 
tioned by that of the ones that have preceded it in the list. 
The factors are listed therefore in the order of increasing 
variability, going from the anatomical through all stages of 
the subjective. As the individual organism ages, however, 
customs become as rigid as instincts, and the latter as inflexible 
as the sense-organs themselves in admitting novel stimuli to the 
focus of attention. Here one has the almost rigid personality, 
where no new ideas enter. Figure 15 represents graphically 
this hierarchy of conditions or selecting factors. 

Accurate Attention. — Interesting experimental data have 
been obtained bearing upon the influence of subjective factors 
in testimony, or accurate attention. These tests have been 
most fully developed by the German psychologist Stern. The 
tests consist in the presentation of objects or events to one or 



120 GENERAL PSYCHOLOGY 

more subjects for description and report. The conditions of the 
experiment are varied in such a manner that it is possible to 
determine among other things the effect upon the range and 
nature of the report of: the duration of the stimulus; the 
presence of surprise in the observer; the age and sex of the 
observer; and the presence of definite expectations or goal 
ideas. We shall now comment upon these factors briefly, so 
far as they deserve additional comment. Attention is most 



V x Y Z 

Fig. 15. — A diagrammatic representation of the conditions of atten- 
tion. V, forces outside the nervous system (they may be inside the body) 
which may or may not affect the sense-organs. X, anatomical conditions 
of attention, the limited numbers, kinds, and capacities of sense-organs. 
Y, conditions of attention such as habit and instinct. Z, the last condi- 
tion of attention, the neural activities immediately preceding any given 
moment of attention. 

efficient if the observer is not fatigued and is not surprised by 
the sudden advent of the experience to be described. Surprise 
is an emotional disturbance, and emotions narrow attention to 
the particular stimuli that arouse them. Surprise thus draws 
attention away from the thing to be described and puts it on 
the characteristic of "unexpectedness" and on the bodily (or- 
ganic) reactions of the observer. Again, trained observers, i.e., 
artists, scientists, report those features of the object which are 
in line with their calling. With untrained observers Stern 
has found evidence that the features of the experience described 



ATTENTION 121 

vary with the age of the observer. Thus, persons and things 
are mentioned at the age of 7 years. From 7-10, actions are 
also noticed. From 12-14, spatial and other relations are 
added, and after 14 come the qualities and properties of the 
objects. Color is one of the last things to be selected. With 
the increasing age of the subject those characteristics of an 
experience are noted which lend themselves to a logical or 
unitary interpretation of the experience observed. There seems 
to be no significant variation with respect to sex in tests of this 
type. Common observation would say that girls and women 
select out or attend to many objects that are ignored by boys 
and men. This, however, is a difference of training and not of 
innate organization. 

By the influence of goal ideas above referred to we mean that 
those objects are most likely to enter the focus of consciousness 
which correspond to the ideas or expectations in the conscious- 
ness of the observer. If I am shown a picture for a few seconds 
and am expecting to see numbers or faint lines, these are certain 
to be attended to. At times these goal ideas are identical with 
what is termed in the study of thinking the Aufgabe, or prob- 
lem at hand. The observer in an experiment is given cer- 
tain instructions. He is thereby prepared to attend to certain 
objects and to pass others by. This preparation is interpreted 
psychologically as a certain cortical set, or preparedness for 
response, by virtue of which nervous impulses in harmony with 
it are facilitated. 

Further Specific Problems in Attention. — So far in our 
account of attention we have been concerned with setting forth 
the general conditions which determine what states of con- 
sciousness, or what neural processes, shall enter the focus of 
greatest clearness. We must now study other phenomena of 
attention such as scope, duration, motor accompaniments, 
fluctuations, divided attention, and classes of attention. Let 
us be perfectly clear with respect to what we are about to study. 



122 GENERAL PSYCHOLOGY 

Describing the matter in terms of consciousness, we want to 
know how many objects can be in the focus at one moment. 
This is the problem of the scope of attention and of divided 
attention. Again, we want to know how long a given object 
can remain in the focus, or, stating the problem in another way, 
how long we can attend to one object (duration of attention). 
In studying fluctuations of attention an attempt is made to 
describe how objects even in the focus of consciousness fluctuate 
in clearness. We shall study the motor disturbances with 
particular reference to the explanation of these fluctuations. 
Let us consider first the scope of attention. 

The Scope of Attention. — Sir William Hamilton was perhaps 
the first to cite an experiment indicating a limit to the number 
of objects that could be distinctly apprehended in a brief interval 
of time. Hamilton says: 

If you throw a handful of marbles on the floor, you will find it 
difficult to view at once more than six, or seven at most, without con- 
fusion; but if you group them into twos or threes, or fives, you can 
comprehend as many groups as you can units; because the mind 
considers these groups only as units, it views them as wholes, and 
throws their parts out of consideration. 1 

This experiment in its modern form is applied to visual 
attention by the means of the tachistoscope. Figure 16 shows 
a typical tachistoscope with a description of some of the cards 
used. The essential characteristic of the apparatus is its adap- 
tation for presenting varying amounts of material, as shown 
on the cards, for brief intervals of time, one one-hundredth to 
one-fifth of a second. Such an interval is too short to permit 
counting, and so the span of attention is measured strictly. It 
has been shown that four or five objects can be grasped during 
the brief exposure. These objects may vary much in com- 
plexity. Four short words can be grasped as readily as four 

1 Sir William Hamilton. Lectures on Metaphysics and Logic (Boston: 
1859), I, 177. 



ATTENTION 



123 



letters; four groups of two lines each (// // // //) can be 
grasped as readily as four single lines. The more significant 
the meaning that is applied to the material the more material 
can be apprehended; e.g., if words are arranged as a sentence 
more words will be apprehended than if they are shown as a 




Fig. 16. — A rotary tachistoscope. The view shows the back of the 
apparatus. The screen D is between the subject and the rotating disk 
S. B is a movable sector by which the angular extent of the adjacent 
opening can be varied. The cards are held in H and are seen by the sub- 
ject through an aperture in the screen when the opening in the disk moves 
by. The cards may contain words, numbers, lines, or any other material 
to be visually discriminated. 



meaningless sequence. The truth of the matter seems to be 
that only one object can be attended to in any single moment. 
This object may be recognized as a complex or as a simple one. 
Experimental analysis shows that the apparent plurality of 
objects in the focus of consciousness is due to rapid processes 
of analysis and does not mean that all are grasped in the same 



124 GENERAL PSYCHOLOGY 

instant. This analysis of the one object into many objects 
follows the presentation of the stimulus in the brief interval 
while the experiences are still vivid. The momentary contents 
of the focus, therefore, and a unitary object are synonymous 
terms. Similar results are obtained with sound. Clicks that 
are given too rapidly to be counted group themselves on the 
average into spans of not more than eight. If, and to the extent 
that, rhythm is introduced within the span of eight, more and 
more sounds may be held in the focus up to thirty or forty. 

There is no good evidence that "divided attention" exists. 
We attend to but one thing at a time. Those famous con- 
temporary and historical personages who do from three to a 
dozen things at once, who dictate several letters and perform 
other tasks all at the same time, are not actually attending to 
all of these matters at once. Attention either shifts with great 
agility from one activity to another, or some of the activities 
are so automatic and habitual that they do not enter conscious- 
ness at all. 

The Duration and Fluctuation of Attention. — In one sense 
we may be said to attend to the same object for many days or 
months. We may attend to the writing of a book, to the direc- 
tion of a journey, or to the creation of a work of art. What is 
really happening of course is that we attend to the writing for 
a few hours only each day, and even during these few hours 
first one aspect and then another of the writing is in the focus 
of attention. In order to test out accurately the question of 
changes in the degree of clearness, it is necessary to work with 
relatively simple objects of low intensity. If one listens to a 
sound that is just barely audible (just above the threshold of 
consciousness) the sound will fluctuate in clearness every five or 
six seconds in spite of all the observer can do. The same thing 
is true if the object fixated is a very faint visual or tactual object. 
The object comes and goes in the focus. If the object is well 
above the threshold the fluctuations in clearness will be so 



ATTENTION 



125 



slight as relatively to pass unnoticed. In illusions of reversible 
perspective, such as the example in Fig. 17, the object is seen 
for a few moments as convex and then as concave. The 
fluctuations are a matter of interpretation or change in meaning. 
Why do these fluctuations of maximal clearness occur? 
What changes are going on in the nervous system and sense- 
organs which determine them? Various answers have been 
offered which may be classified as central and peripheral theories, 




Fig. 17. — An illusion of reversible perspective (after Titchener). 
The illusion consists in seeing the stairs sometimes as from above and 
sometimes as from beneath. 



according as they attribute the essential conditions to the 
brain or to the sense-organs. Back of this type of explanation 
lies the larger question concerning the biological purpose or 
value of the fluctuations. This has been stated by Angell 
essentially as follows: Consciousness is concerned with the 
adjustment of the organism to its environment, with the solu- 
tion of problems. Adjustment is a matter of detail; so that 
as each detail is disposed of, consciousness passes to another. 
The hypothesis, although alluring, has two apparent points of 
weakness. It would give consciousness an influence over bodily 



126 GENERAL PSYCHOLOGY 

activity; or, if it were so phrased as to escape this difficulty, 
it would still be unable to meet the second one, viz., the matter 
of the regularity of the fluctuations. Why should each process 
of problem solution occupy an approximately equal length of 
time? What seems a more probable answer, although an 
equally speculative one, is that the evolution of a highly com- 
plicated and delicately adjustable nervous system has evidently 
involved the appearance of one that is intrinsically unstable. 
This harmonizes well with the specific theory of explanation 
referred to above as the central theory. 

Very strong argument has been brought forward to prove 
that the fluctuations are due to variations in the efficiency 
with which the sense-organs function. Thus the muscles of 
accommodation in the eye (or even the retina itself) may change 
through fatigue in such a manner as to decrease the clearness 
of the object in the focus. Influences of this type may often 
be effective, but they cannot by themselves account for the 
regular recurrence of the fluctuations. This is one important 
reason for not placing chief reliance upon the peripheral theory. 

The central theory assumes that the fluctuations in clearness 
are due to the fatigue and recovery of cortical cells. It is 
supported by the observed fluctuations in ideas (images), 
illustrated by the reversible illusion (Fig. 17), by cases where 
sense-organs are not involved, and by the failure of peripheral 
theories to explain the facts. Furthermore, the regularity of 
the fluctuations lends support to the theory, for this regularity 
can be credited to certain waves of nervous excitation which 
originate in the medulla and probably spread to the cortex. 
These are the Traube-Hering waves of variation in blood 
pressure. Their spread to the cortex would result in alternate 
heightening and lowering of brain activity. The result of 
these waves, or rhythms of activity, in the medulla can be 
measured through the increase and decrease of the volume of 
the arm. These rhythms of increased pressure occur about 



ATTENTION 127 

every six seconds and have been found to occur simultaneously 
with the fluctuation in attention. In certain instances similar 
variations in the breathing rhythm have been noted which also 
ran parallel with the changes in attention. 

Classes of Attention. — The many instances of attention are 
usually grouped into three classes on the basis of the manner 
in which the feeling of effort is involved: voluntary, involun- 
tary, and non-voluntary or spontaneous attention. At the 
present moment, e.g., the reader's effort is directed toward 
keeping the topic of psychology in the focus and keeping out of 
the focus all distracting influences. This is voluntary atten- 
tion. If in spite of the effort a sudden noise breaks into the 
focus, the attention to the noise is termed involuntary. Other 
instances of this type of attention may be drawn from the field 
of imagery — an idea may haunt the mind continually after it 
is once encountered (fixed idea), or a tune may run in one's head 
constantly in spite of all effort to be rid of it. In the third 
form of attention the object which enters the focus of con- 
sciousness is neither aided nor opposed by effort. It appears 
spontaneously as in reverie and as in the cases of free association 
described in the account of psychoanalysis (p. 80). It is un- 
doubtedly correct to regard spontaneous attention as the type 
present in the newly born animal or man. The nervous impulses 
that stand at the center of cortical activity, or, in other terms, 
the objects that enter the focus of consciousness, represent, not 
the product of effort, but the effect of innate nervous organiza- 
tion. Attention to the loud noise and to the bright light is 
spontaneous at this level because these events do not interrupt 
organized sequences of thoughts and sensations (objects). As 
soon as these organized plans and interests arise, voluntary and 
involuntary attention is clearly possible. When the young 
organism has acquired sufficient experience to choose and 
select, then that which interrupts or breaks in upon him is 
the involuntarily attended to object. This form of attention 



128 GENERAL PSYCHOLOGY 

is practically always unpleasant in varying degree, and is 
inseparably bound up with the emotion of surprise. 

Unfortunately the terms voluntary, involuntary, and 
spontaneous do not lend themselves readily to descriptions of 
behavior where no reference to consciousness is involved. And 
yet distinctions of this type can be drawn with advantage 
between forms of behavior. For example, a dog is hungry and 
starts over toward his food bowl. This temporarily dominant 
form of response takes place unopposed and spontaneously. 
Now suppose that his master leaves the room and that because 
of the strangeness of the place the dog has a strong tendency 
to follow. Here are two opposite tendencies to response. If 
in spite of the impulse to follow his master the animal reacts 
to the food, the behavior situation is on a par with involuntary 
attention. So far as one describes this same situation in terms 
of obedience to the food-getting impulse, it is similar to volun- 
tary attention. In like manner one may follow through cases 
in human behavior where responses are made to a simple situa- 
tion and to situations involving competing impulses. 

In concluding this section it may be said that a classification 
of attention such as we have just outlined is not a classification 
of different types of "clearnesses"; it is a division of attention 
on the basis of the relation existing between the content of the 
focus of consciousness (area of maximal clearness) and the 
awareness of effort. This awareness of effort is the conscious 
side of some of the motor accompaniments of attention to be 
described in the following section. 

Motor Accompaniments. — If we concentrate attention upon 
a very faint sound there is an irresistible tendency to stop 
breathing, to tighten many muscles in the upper part of the 
body, to turn one ear in the direction of the sound, etc. These 
are the readily observable motor changes. In addition, there are 
probably adjustments in the muscles of the middle ear favoring 
more acute hearing, as well as changes in circulatory processes. 



ATTENTION 129 

If the object attended to is a visual one of low intensity, there 
are, in addition to the general bodily disturbances of the type 
just described, other changes which serve to adjust the eyes for 
better vision. The eyes are focused upon the object; changes 
occur in the width of the pupil and in the shape of the lens; 
the eyes are turned in their orbits; and finally the brows are 
contracted. Changes of this nature which serve to make 
the sense-organs more sensitive are changes of accommoda- 
tion. Other motor accompaniments of attention are the non- 
accommodatory changes. The tendency is for changes of both 
types to be absent in spontaneous attention, the characteristic 
motor attitude here being one of relaxation. It is undoubtedly 
this which makes spontaneous attention devoid of the conscious- 
ness of effort. The function of the motor accompaniments of 
accommodation has been stated and is readily understood. 
However, the function of the non-accommodatory changes is 
less easily seen. Undoubtedly they serve to arouse nervous 
impulses which facilitate (aid) those other nervous changes 
which are in the focus of activity and indirectly inhibit (oppose) 
any competing nervous activity. 

A great many studies have been made of the circulatory and 
respiratory changes in an effort to correlate specific changes in 
them with the presence and absence of voluntary attention. 
Investigators have sought for these differences in the rate and 
amplitude of respiration and in the rate and character of the 
heart-beat. In these experiments the subject is seated com- 
fortably and is given various problems in mental arithmetic 
to solve, or is asked to listen to reading, or is instructed to con- 
centrate attention upon a given object, etc. It is important 
that no disturbances occur to interfere with bodily comfort or 
with the direction of attention. The apparatus used in the 
study of breathing is called a pneumograph and is shown in 
Fig. 18 in connection with the smoked-paper writing surface 
on the kymograph drum. The results obtained by this method 



13° 



GENERAL PSYCHOLOGY 



show great divergence, but they probably justify the statement 
that breathing tends to become shallower and more rapid in 
concentrated attention. In studying the circulatory changes 
a plethysmograph may be used, which is merely an air- or 




Fig. i 8. — The apparatus A is a kymograph. The drum rotates at a 
variable speed and is driven by a spring within the base. 

The apparatus B is a pneumograph. The tape at G and G is placed 
around the subject's body so that expansion and contraction will pull 
upon the rubber membranes attached to D. These changes are trans- 
mitted as puffs of air in the tubes F, F, and H. They finally reach a marker 
which records on the kymograph drum. 



water-filled chamber into which the finger or hand may be 
placed. Pulse-beat and Traube-Hering waves may then be 
registered on the smoked paper of a revolving drum. Here 
again the results obtained are variable, but indicate that the 



ATTENTION 131 

volume of the arm decreases with sustained attention (Stevens) 
and that the heart-rate increases (Shepard and Billings). How- 
ever, much additional experimental work needs to be done in 
order to clarify the question of the part played in attention by 
these non-accommodatory movements. 

Our brief account of attention brings us constantly back 
to the conception of the individual which was sketched above. 
We may think of each animal organism, whether man or below 
man, as a more or less independent unit played upon through 
the senses by various forces and as responding with muscular, 
glandular, and conscious activity. In adjusting itself to 
environmental demands, certain behavior must dominate at 
one moment and certain other behavior at the succeeding 
moment. This dominance and this variation are the behavior 
counterparts of what subjectively is termed attention. From 
the conscious side those objects are attended to which stand 
out in clearness or which dominate at a given moment. 

REFERENCES 

Angell, J. R. Psychology, chap. iv. New York: 1908. 

Ferree, C. E. "An Experimental Examination of the Phenomena 

Usually Attributed to Fluctuations of the Attention," Amer. 

Jour. Psych., XVII (1906), 81-120. 
Gamble, E. Mc. "Attention and Thoracic Breathing," Amer. Jour. 

Psych., XVII (1905), 261-92. 
McComas, H. C. "Types of Attention," Psych. Rev. Mon., XIII 

(1910), No. 3. 
Pillsbury, W. B. Attention. New York: 1908. 
Shepard, J. F., and Billings, M. L. "Changes in Heart Rate with 

Attention," Psych. Rev., XVII (1910), 217-28. 
Stevens, H. C. "A Plethysmographic Study of Attention," Amer. 

Jour. Psych., XVI (1905), 409-83. 
Titchener, E. B. Elementary Psychology of Feeling and Attention. 

New York: 1908. 
Woodrow, H. S. "Faculty of Attention," Jour. Exper. Psych., I 

(1916), 285-318. 



CHAPTER II 

THE NERVOUS SYSTEM 

The Reasons for Study. — Psychologists study the nervous 
system for three chief reasons: (i) Consciousness is intimately 
correlated with nervous processes. We have been reminded 
of this fact constantly in our study, and in the preceding chapter 
on "Attention" we were forced to turn specifically to theories 
and descriptions of nervous activity for explanations. At the 
present point we shall cite three typical cases of the relation of 
consciousness and bodily activity: (a) It is through the sense- 
organs and nervous system that such changes as air-vibrations, 
ether-waves, and chemical and mechanical impacts affect con- 
sciousness. The philosophers have termed this "the acquisi- 
tion of knowledge of the external world." (b) Accidents to the 
nervous system, particularly to the brain, will change conscious- 
ness (cause loss of certain conscious states, confusion, etc.), 
or may even abolish it entirely, (c) Disease and drugs pro- 
foundly modify nervous conditions, and corresponding conscious 
changes take place. (2) A second reason for the study of the 
nervous system lies in the fact that the nervous system, by 
virtue of its continued existence, offers an explanation of much 
that occurs in consciousness. The instances of particular 
importance are those of learning and memory, i.e., of acquisition 
and retention — two phases of the same thing, because in order 
to complete learning it is necessary to retain, the progress of the 
earlier stages. States of consciousness cease to exist the moment 
We are unaware of them. They are not stored away in some 
recess of the head or of the mind, thence to be recalled as occa- 
sion warrants. The accompanying processes in the nervous 
system modify the nervous tissue, and these modifications are 

132 



THE NERVOUS SYSTEM 133 

retained, a re-excitation of which reinstates the conscious experi- 
ence. (3) The third reason lies in the fact that the nervous 
system controls behavior. Its function is the co-ordination of 
receptors and effectors. 1 Nervous impulses come in from 
receptors and are transmitted to effectors on the basis of con- 
nections or associations set up either by heredity or by the indi- 
vidual's own experience. In no other manner can the organism 
initiate activity. 

The study of the nervous system is not a non-psychological 
study) for it cannot be divorced from behavior. Most researches 
made on the nervous system are made in the physiology and 
anatomy laboratories, not because all, or even most, of the 
results are non-psychological in character, but because few 
psychologists have the necessary training and interest to work 
in this field. This we shall see to be likewise the case in many 
studies of sensation. 

The Neurone. — We shall begin our study with the neurone, 
which is the structural unit of the nervous system. It is com- 
posed of a cell-body, dendrites, and an axone. The entire nervous 
system is built up of cells many of which are these true nerve- 
cells, but many of which are supporting ones, neuroglia, non- 
nervous in function. Figure 19 shows typical nerve-cells and 
their attached filaments. A neurone differs from other cells in 
the body in that its special function is the conduction of energy, 
the nervous impulse. This function we saw on page 20 to be 
one of the general characteristics of protoplasm. Beginning 
students often get the impression that neurones are always 
microscopic in size, a condition that is frequently true. All are 
microscopic in diameter, but many of them are several feet in 

1 The term receptor is preferable to sense-organ because not all receiving 
structures connected with the nervous system arouse sensations or sensory- 
processes. The term ejfector is more convenient than the phrase "muscles 
and glands." It refers to the structures that are aroused to activity by 
nervous impulses and that are connected with a motor nerve fiber. 



134 



GENERAL PSYCHOLOGY 



length. One neurone, for example, extends from the top of 
the brain (pre-Rolandic area) to the lower part of the spinal 
cord at about the level of the first sacral vertebra (in the small 
of the back). Again one neurone may extend from the sacral 




Fig. 19. — Typical neurones (from Morris) 

"A. From spinal ganglion. B. From ventral horn of spinal cord. 
C. Pyramidal cell from cerebral cortex. D. Purkinje cell from cerebellar 
cortex. E. Golgi cell of type II from spinal cord. F. Fusiform cell from 
cerebral cortex. G. Sympathetic, a, axone; d, dendrites; c, collateral 
branches; ad, apical dendrites; bd, basal dendrites; cc, central process; 
p, peripheral process." 



region of the cord to the tip of the toe. The cell-bodies them- 
selves range in size from 1/160 to 1/6,000 of an inch in diameter; 
the axones, from 1/2,000 to 1/100,000 of an inch in diameter. 
As many as 100,000 of these latter may be bound together like 
a cable with connective tissue to form a nerve. 



THE NERVOUS SYSTEM 



135 



The cell-body contains at least two substances of great 
importance: the neurofibrils, shown in Fig. 20, and chromatin. 
The former extend out into the axones and may serve in the 
conduction of the nerve impulse. The chromatin (so named 
because of the ease with 
which it takes up the stains 
used in microscopic work) is 
intimately concerned in the 
metabolism of the neurone. 
When an animal has been 
excessively fatigued, micro- 
scopic examination of the 
cell-bodies shows that the 
chromatin has broken down 
and is scattered in small frag- 
ments throughout the cell- 
body. This is called chro- 
matolysis (see Fig. 21). It 
sometimes even happens 
that the exhaustion is so 
complete that the cell-walls 
themselves break down and 
the neurone degenerates and 
is absorbed. The probable 
function of the cell-body is 
the nutrition of the neurone. 
It may incidentally slow 
down the transmission of the 
nerve impulses. In times 
past it has been regarded as 
the seat of ideas, as the most important part of the nervous 
system, and as the possible originator of many nerve impulses. 
It is still possible to view some sudden metabolic change in the 
cell-body as an occasional cause of nerve impulses. 




Fig. 20. — The cell-body of a neu- 
rone stained to show the neurofibrils 
(after Bethe). 



136 



GENERAL PSYCHOLOGY 



The axone is efferent in function, that is, it conducts the 
nerve impulse away from the cell-body. Typically there is 
only one axone to a neurone, and it is smooth in outline, with 
branches at right angles. The dendrite is afferent in function, 
that is, it conducts the nerve impulse toward the cell-body. 
The number of dendrites per neurone varies from one to a great 




Fig. .21. — Cell-bodies of two motor neurones showing chromatolysis. 
B is the more advanced stage (from Herrick after Cajal). 

number, and they are usually rough in contour with their 
branches at oblique angles. These facts are shown in Fig. 19, 

P. 134. 

All axones of the central nervous system (see p. 144) and 
the dendrites of the neurones composing the spinal sensory 
nerves are covered with a myelin or medullary sheath, a fatty 
substance secreted by the neurone, Fig. 22. This sheath serves 
to insulate and support the inclosed axis cylinder and may play 



THE NERVOUS SYSTEM 



137 



some further part in the conduction of the impulse. It is white, 
and axones covered with it make up the major part of the 
"white" portion of the spinal cord 
and brain. The axones of the sym- 
pathetic nervous system (see p. 
144) lack this covering and are gray 
in appearance. Those axones and 
dendrites that belong to the cerebro- 
spinal system and yet lie outside the 
central nervous system (the fibers of 
the peripheral nerves) possess a second 
sheath, the neurilemma, which prob- 
ably functions in the regeneration of 
a destroyed fiber, Fig. 22. If a motor 
nerve is cut outside the spinal cord, 
the fibers degenerate, and the person 
is temporarily paralyzed in certain 
muscles. The cells making up the 
neurilemma, however, do not degen- 
erate. In the course of time a new 
nerve fiber is developed, and the 
paralysis disappears. If on the other 
hand the injury, or lesion, occurs in 
the spinal cord or brain where the 
neurilemma is absent, the pathway 
interrupted either never regenerates 
or else does so very slowly. In these 
cases the paralysis or the anaesthesia, 
loss of sensation, may be perma- 
nent. Where recovery of function 
does occur, it is most probably 
due to certain other structures 
taking over the function of the 
destroyed tissue (so-called vicarious functioning). 



Fig. 22. — Fragments of 
two nerve fibers. The outer 
white layer is the neuri- 
lemma. The black sheath 
is the medullary one. The 
gray central portion is the 
axis cylinder. 



138 



GENERAL PSYCHOLOGY 



The Reflex Arc. — The functional unit of the nervous system 
is the reflex arc. By this statement is meant that the reflex 
arc is the least segment of nerve tissue that can carry out the 
function peculiar to this system, viz., the correlation of receptors 




Fig. 23. — Cross-section of the spinal cord. The inner H -shaped 
figure gives the outline of the gray matter. The remainder is white 
matter. D, dorsal; V, ventral; sg, spinal ganglion; c, spinal canal; 1,1, 
are crossed pyramidal tracts containing fibers from the pre-Rolandic area 
of the brain; 2, 2, are direct pyramidal tracts carrying the same type of 
motor nerve fibers from the brain. The crossed fibers cross from one 
side to the other of the cord in the region of the medulla. The direct 
fibers cross at lower levels. The arrows indicate the direction of the 
nervous impulse. 



and effectors. The reflex arc includes at least two neurones 
and usually many more. It may be further defined as any 
nervous pathway between a receptor and an effector. Figure 23 
represents a cross-section of the spinal cord and several simple 
reflex arcs. If more than two neurones are involved, all but 
the first and last are termed association neurones. ' The first 



THE NERVOUS SYSTEM 139 

one is the afferent or sensory neurone, while the last one is the 
efferent or motor neurone. 

The union between two neurones is the synapse. This con- 
nection is physiological (functional) and not anatomical (i.e., 
there is no tissue continuous from one neurone to the other). 
The figure above makes clear the statement that the determina- 
tion of the pathway over which a nerve impulse shall pass is 
made at the synapse. In this figure the nervous impulse comes 
in from the skin to the spinal cord. Here it may go over either 
one or both of the two pathways. The direction which it 
does take depends upon the relative amounts of resistance 
encountered at the two synapses, for the impulse takes the 
path of least resistance. What the exact nature of this resist- 
ance is we are unable to say. It may be due either to chemical 
or to mechanical changes. 3 Learning or habit-formation is 
synonymous with the elimination of certain pathways so that 
more and more of the nerve impulse is carried exclusively to a 
certain muscle or set of muscles. Intelligence, too, is largely a 
question of the particular synaptic connections that function 
in a given individual.^ An individual would not be rated as 
intelligent if a pain impulse resulted in such a contraction of 
the muscles as to lead to retention of the injurious object; nor 
is one intelligent whose muscles respond as a laugh when they 
should bring forth a sob. What response shall be made depends 
fundamentally upon the synaptic connections available, either 
as inherited and thus instinctive, or acquired and thus habitual. 
We shall canvass the factors underlying the setting or formation 
of these associations later in the chapters on "Instinct" and 
"Memory." 

The Development of the Nervous System. — A glance for- 
ward to Fig. 25 will convince the reader that if any key to the 
complexity of the human nervous system is available it should 
be utilized. The development of nerve structures in the evolu- 
tion of organisms and in the embryology of the individual 



140 



GENERAL PSYCHOLOGY 



furnishes such a key. We have already seen the condition in 
protozoa, unicellular organisms (p. 20), where there is no 
structural differentiation of the system. The first important 
step for our purposes after this stage is the appearance of a 
diffuse nerve net such as is found in the jelly-fish. Impulses 
may start at any one of its sensory patches and pass in any 
direction to affect the muscles of the body and tentacles. 
Figure 24 represents a higher stage of evolution, the nervous 




Fig. 24. — A lateral view of the nervous system in the anterior end of 
an earthworm (after Hesse from Shipley and McBride) : 2, the brain or 
cerebral ganglion; 3, connecting bands of nerve tissue; 4, first ventral 
ganglion; 5, the mouth; 8, 9, 10, nerves. 



system of the earthworm. In the anterior segment of the worm 
is a ganglion, or mass of nerve tissue, termed the brain. Below 
the alimentary canal lies the ventral nerve cord which duplicates 
in essentials of structure the spinal cord of man and other 
vertebrates to be described. 

Provisions exist in the nerve cord of the worm whereby 
afferent nervous impulses may pass out immediately as efferent 
impulses or whereby they may pass up or down the cord a 
greater or lesser distance. The ordinary locomotion of the worm 
involves primarily short association neurones, whereas the sud- 
den contraction of the whole body upon injury is due primarily 



THE NERVOUS SYSTEM 141 

to the activity of long fibers. Yerkes has shown that simple 
maze-habits established by normal worms persist even after 
the head has been removed from the body. Apparently the 
chief difference between the normal and the headless worm 
lies in the less variable behavior of the latter. The evolution 
of the nervous system from the worm to man involves the 
following changes fundamental to behavior: (a) an increase 
in the complexity of the head ganglion or brain; (b) an increase 
in the number of long connections within the cord, making the 
cord more of a unit as opposed to the condition in the worm, 
where each segment is fairly independent; and (c) an increase 
in the mutual relations between brain and cord, a more com- 
plete unity of all nervous action. 

The human nervous system is essentially a hollow tube much 
modified and enlarged at the anterior end. The spinal canal 
shown in Fig. 23 is part of the inner cavity of the tube and 
is continuous with the four large ventricles or cavities of the 
brain. The embryological development takes place in the 
following manner: Nervous tissue begins as a thickening in 
the ectoderm on the dorsal side of the embryo. This neural 
plate folds in, or invaginates, and closes over, thus forming the 
neural tube. At the anterior end three enlargements, primary 
vesicles, appear by an unequal thickening of the walls of the 
tube. From these three vesicles the brain develops by a series 
of outgrowths and flexions into the form to be described below. 
Along the main body of the tube or cord outgrowths occur 
which develop into the spinal nerves and into the sympathetic 
nervous system. Our discussion will now deal with the struc- 
ture of the adult nervous system and the functions of its various 
parts. 

Divisions of the Adult Nervous System. — The nervous 
system is composed of two main divisions: the cerebrospinal 
system and the sympathetic system. The essential topographi- 
cal relations of the two are shown in Figs. 25 and 26. The 



142 



GENERAL PSYCHOLOGY 



SUPERIOR CERVICAL SYM-' 
PA THE TIC OA NG L ION 



MIDDLE CERVICAL SYMPATHETIC 
GANGLION 



INFERIOR CERVICAL SYMPA- 
THETIC GANGLION 



GANGLIATED COED 




1 CERVICAL NERVE 



H "-I THORACIC NERVE 



GANGLION -- 



I LUMBAR NERVE 



SACRAL NERVE 



M COCCYGEAL NERVE 



FILUM TER'MINALE 



Fig. 25. — Ventral aspect of the major portion of the cerebro-spinal 
system, showing also one of the chains of sympathetic ganglia (from 
Morris). The numbers point out the 31 pairs of spinal nerves. The 
large mass of nervous tissue at the top is the cerebrum. The smaller 
dark striped mass is the cerebellum. The 12 pairs of cranial nerves are 
shown (unnumbered) above the spinal nerves. 



THE NERVOUS SYSTEM 



143 



Maxillary nerve 

Ciliary ganglion 
Sphenopalatine ganglion \ 
Superior cervical ganglion of sympathetic \ \ 



Cervical plexus 



Brachial plexus 



Greater splanchnic nerve 
Lesser splanchnic nerves 



Lumbar plexus , 



Sacral plexus 




Pharyngeal plexus 

Middle cervical ganglion of 

sympathetic 
Inferior cervical g. of sympathetic 
Recurrent nerve 

Bronchial plexus 

Cardiac plexus 



1 Esophageal plexus 

- ^Coronary plexus 



Left vagus nerve 

Gastric plexus 
Celiac plexus 

Superior mesenteric plexus 



Aortic plexus 

Inferior mesenteric plexus 

—37 Hypogastric plexus 

Pelvic plexus 

Bladder 
Vesical plexus 



Fig. 26. — Showing the sympathetic nervous system in some of its 
widespread ramifications (after Schwalbe from Herrick). The Roman 
numerals again refer to spinal nerves (plus the Vlth and Xth cranial 
nerves). The diagram also indicates the location of the chief parts of the 
nervous system with reference to the body in general. 



144 GENERAL PSYCHOLOGY 

sympathetic system, which is intimately connected anatomically 
and physiologically with the cerebro-spinal system, is composed 
of the following parts: (i) a chain of ganglia lying ventral to 
and on either side of the spinal cord; (2) three or four large 
masses of nerve tissue called plexuses lying in the body cavity 
and in close connection with the organs controlled; and 
(3) smaller ganglia scattered throughout the organism, in the 
eye-socket, in the thoracic cavity, on the walls of the heart, and 
elsewhere. Its function is the control of the action of glands 
and smooth muscles, activities such as the secretion of saliva, 
the peristalsis of the alimentary canal, and the variations in the 
tension of the arterial walls. In addition afferent impulses 
come from all of the viscera to sympathetic ganglia and often 
go on into the spinal cord. Here they may be transferred and 
reach the brain, giving rise in consciousness to organic sensa- 
tions (hunger and intestinal distress) and transferred pain 
(headaches, for example, due to visceral disturbances). Some 
details of this we shall have occasion to consider in the chapter 
on "Sensation" (p. 215). It is in relation to the emotions, 
however, that the sympathetic system has its greatest signifi- 
cance for psychology, for, as we shall see in our chapter on that 
topic, organic disturbances are the factors of primary importance 
in our emotional experiences. The cerebro-spinal system in- 
cludes the central nervous system and the peripheral nervous 
system. The former includes the spinal cord and brain; the 
latter is composed of the cranial and spinal nerves. 

The Structure and Function of the Spinal Cord. — Figure 23 
has already made us familiar with the cord in cross-section and 
with reflex arcs. A nerve impulse may come in over any one 
of the afferent fibers from some sense-organ in the skin, pass 
by association neurones to any other efferent neurone at the 
same level of the cord or at some other level, and from there 
go out to a muscle or gland. These afferent and efferent fibers 
at any one level of the cord are bound together to form the 



THE NERVOUS SYSTEM 145 

spinal nerves, sensory and motor, of which there are thirty-one 
pairs. The sensory impulses that come in over these nerves 
condition kinaesthetic (muscle, joint, and tendon), organic, 
and cutaneous sensitivity in consciousness. Figure 2 7 illustrates 
a cross-section of the cord, showing extensive degenerations in 
the dorsal portion. 




Fig. 27. — Degeneration changes in the spinal cord from tabes (from 
Jelliffe and White). Practically all of the dorsal part of the white matter 
has degenerated and is shown in lighter gray. 

The function of the cord is: (1) to convert sensory impulses 
directly into motor impulses; and (2) to transmit impulses to 
upper or lower levels of the nervous system. We shall now 
indicate how these functions are performed by certain essential 
and typical structures. The cell-body of the first, the sensory, 
neurone always lies in the spinal ganglion, 1 while that of the 
motor neurone lies in the ventral or in the central part of the 
spinal gray matter. The gray matter of the cord is composed 

X A ganglion is any group of nerve-cells outside the central nervous 
system. 



146 GENERAL PSYCHOLOGY 

largely of cell-bodies and unmedullated fibers, the white matter 
consisting of medullated fibers passing up and down the cord. 
Fibers and cell-bodies having similar functions are grouped 
together both in the white matter and in the gray, forming, 
respectively, fiber tracts and columns or nuclei. The only 
further detail we need mention is the location of the pyramidal 
tracts, crossed and uncrossed, which contain fibers originating 
from cell-bodies in the pre-Rolandic area of the cerebral cortex. 
Impulses pass down over these and produce voluntary move- 
ments of muscles. All of these fibers finally cross to the opposite 
side of the body from which they originate, so that the left side 
of the brain is connected with the right side of the body and 
vice versa. Sensory impulses passing to the brain go over 
certain definite pathways also, but they need not claim our 
attention. Any lesion due to accident or disease in these path- 
ways in the cord results in such characteristic disturbances of 
movement and sensation as to enable the clinician to diagnose 
the location of the lesion fairly accurately. In locomotor ataxia, 
or tabes, for example, the germs attack the posterior columns of 
white matter (Fig. 27) . As a consequence of the resulting loss of 
touch and kinaesthetic sensations, the individual is unable to con- 
trol properly the movements of his feet and legs. Vision is there- 
fore used as a guide, but even with this aid a characteristic gait 
is evident, caused by the absence of necessary sensory impulses. 
The Medulla. — Figure 25 should be consulted in order that 
the student may have clearly in mind the mutual topographical 
relations of the parts of the brain, for we shall now deal with 
the second division of the central nervous system. The medulla 
is about one inch long and is a continuation of the spinal cord. 
Nerve impulses pass through it to the cerebrum and cerebel- 
lum as well as down it to the spinal cord. In addition it con- 
tains nerve centers 1 which control circulation and respiration. 

1 The term nerve center applies to any group of nerve-cells in the brain 
which has a definite function. 



THE NERVOUS SYSTEM 147 

When the carbon dioxide content of the blood, e.g., becomes ab- 
normally high, as in approaching asphyxia, this chemical con- 
dition acts upon centers in the medulla with the result that the 
heart-beat is increased in rate and respiration is accelerated and 
deepened. (We spoke of this above in an account of tropisms, 
p. 21.) Both cerebro-spinal and sympathetic nervous sys- 
tems are involved in this action of the medulla. 

The Cerebellum. — The cerebellum is composed of two 
hemispheres connected by the pons and bound by many fibers 
to the medulla and mid-brain. The chief function of this divi- 
sion of the brain is the maintenance of bodily equilibrium. 
To this end sensory impulses are received from the skin, muscles, 
and joints, from the semicircular canals of the ear, and from the 
eyes. The stopping of any of these classes of nerve activity 
interferes tremendously with equilibrium. We have noticed 
it already in locomotor ataxia. It can be shown by closing the 
eyes and attempting to stand without swaying, or in laboratory 
work by extirpating the semicircular canals of animals. If the 
injury is as great as the total excision of the cerebellum, the 
animal is entirely unable to maintain its balance. Impulses 
from the cerebellum serve also to maintain proper muscular 
tonus (contraction) and thus aid voluntary movement. It is 
probable that all portions of the cerebellar cortex, or outer 
gray layers, have the same function. So far no evidence has 
been produced indicating that consciousness is correlated with, 
or directly conditioned by, nervous activity in this cortex. 

The Mid-Brain. — The dominant structure of this part of the 
brain is the corpora quadrigemina (superior and inferior col- 
liculus), whose function is that of auditory and visual reflexes. 
Sensory impulses coming from the eyes (retinae) and ears 
(cochleae) enter here into synaptic connections with many 
motor neurones to the face, eyes, and other parts of the body. 

The Thalamus. — The thalamus is a large mass of nerve 
centers lying in the center of the brain. All sensory impulses 



148 GENERAL PSYCHOLOGY 

go^ through some part of this structure before reaching the 
cerebral cortex, with the exception of certain impulses from the 
nose (olfactory membrane) coming over the first cranial nerve 
which arrive at the cortex by a different route. Clinical 
observations indicate that sensory impulses undergo much 
elaboration in the thalamus probably in the way of associa- 
tion with other afferent impulses so that a part of the neural 
correlate of conscious complexity arises before the neural excite- 
ment reaches the cortex (Herrick and Rahn). Studies of uni- 
lateral thalamic lesions by Head and Holmes have presented 
evidence that emotional and affective (pleasantness and 
unpleasantness) conscious states have their accompanying 
neural activity in the thalamus. Individuals with such lesions 
have excessive enjoyment of warmth or of concerts, for example, 
upon the affected half of the body. The evidence from this 
work further points to the general inhibitory influence of the 
nervous processes of the cerebral cortex upon those of lower 
portions of the brain. 

The corpus striatum, a nerve center lying between the 
thalamus and the cerebral cortex, is another correlation center. 
Like the thalamus, it offers further opportunity for the elabora- 
tion of sensory impulses before they reach the cortex. In 
each case the sensory impulse may pass over a motor neurone 
originating in these correlation centers and a reflex act result 
without involving the cortex. 

The Cerebral Cortex. — 'The neural processes which occur 
in the cerebral cortex comprise the major part — if not all — of 
those physiological activities which are directly correlated with 
consciousness. The remainder, if there are any, occur in the 
thalamus. The cortex is the highly convoluted layer (rind) of 
gray matter about 4 mm. thick which covers the cerebrum as a 
whole. Figure 28 shows this fact and also the topographical 
relations of the cortex to the other nerve centers which we have 
been describing. Unlike the cerebellar cortex, that of the 



THE NERVOUS SYSTEM 



149 



cerebrum is highly differentiated in function. Figure 29 names 
the primary lobes and their accepted functions. To designate 
the occipital lobe as the 'Visual center" means that sensory 
impulses from the retina of the eye reach this part of the brain 



, BODY OF CORPUS CALLOSUM 



THALAMUS -; 
THIRD VENTRI- 



TNFERIOR CORNU 
OF LATERAL 
VENTRICLE 




OCULO-MOTOR 
NERVE 



TRKSFMINAL 
NER VE 



FACIAL AND 

ACOUSTIC 

NERVES 



GLOSSO-PIIARYN- 

OEAL NERVE 
■S NERVE 



CEREL 



SUPERFICIAL FIBRES OF PONS 

PYRAMID 



DECUSSATION OF PYRAMIDS 



Fig. 28. — A vertical section through the brain (after Toldt, Alias of 
Human Anatomy, by permission of Rebman Co., New York). Fibers are 
faintly indicated passing from the cord to various portions of the brain. 



and that any disease or accident affecting it modifies visual 
consciousness primarily. Visual sensations and ideas (and the 
same applies pari passu to the other sensory centers) are not 
in the occipital lobe. They are wherever we are aware of them. 



IS© 



GENERAL PSYCHOLOGY 



■> - — <r^ ^.^t ~-~^_- CI 



PARIETAL ASSOCIA 
TION CENTRE 




FRONTAL 
ASSOCIA- 
TION 
CENTRE 



CCIPITO- TEMPORA L 
ASSOCIATION CENTRE 



AUDITORY AREA 



SOMJZSTHETIC AREA 



PARIETAL ASSOCIA- 
TION CENTRE 



FRONTAL X 
ASSOCIA TION 
CENTRE 




VISUAL 
AREA 



OCCIPITOTEMPORAL 
ASSOCIATION CENTRE 



OLFACTORY AREA 



Fig. 29. — Diagrams of the two sides of the left cerebral hemisphere, 
indicating the localization of functions (from Morris). Visual area in 
occipital lobe; auditory area in temporal lobe; H, the hippocampal lobe. 
The somaesthetic area lies on both sides of the fissure of Rolando, the pre- 
Rolandic area being the area for voluntary movement and the post-Rolandic 
area receiving impulses for the skin, muscles, joints, tendons, and viscera. 



THE NERVOUS SYSTEM 151 

Figure 30 shows the chief fiber tracts within the brain, in addi- 
tion to which are innumerable smaller ones connecting adjacent 
parts of the cortex. 

The following are the chief methods that have been used 
in mapping out the localization of functions which were sche- 
matically presented in Fig. 29: (1) The anatomical method 




Fig. 30. — Chief fiber tracts in the brain (after Starr from Judd). 
The Roman numerals indicate the cranial nerves. The dotted mass in 
the center is the thalamus. Just anterior and dorsal is another mass, the 
corpus striatum. 

is used in tracing the fibers from a given sense-organ to their 
ultimate cortical destination and from the motor areas to lower 
centers. Very important is the fact that degenerated nerve 
fibers stain differently from normal fibers and that fibers degen- 
erate not toward but away from their cell-body. By experi- 
mentally sectioning certain tracts in animals and by observing 



152 GENERAL PSYCHOLOGY 

postmortem the effects of lesions in man, it has been possible 
to construct fairly definitely the functional pattern of the 
cortex. In addition to this fiber-degeneration method, there 
is the method of mapping cell patterns. The cortex contains 
many different types of cells which vary in the patterns of 
their relative distribution from one part to another of the 
cortex. Figure 3 1 shows a section from each of two well- 
marked cortical areas, the pre-Rolandic area for voluntary 
movement and the occipital lobe for vision. (2) The physio- 
logical method attempts to formulate the function of a given 
brain area by noting the effect of its activity upon the behavior 
of the animal. Parts of the brain are removed and modifications 
in the animal's sensitivity and motor capacity studied. This 
method gives more reliable results when applied to the deter- 
mination of the motor areas, for here we can stimulate elec- 
trically the exposed brain of an animal and record the muscles 
which contract. Tests have been made on the exposed brain 
of man in certain cases, and results have here been obtained 
similar to those secured on monkeys and dogs. In one case 
it was even possible to arouse a cutaneous sensation in the hand 
by stimulating a portion of the post-Rolandic area (Gushing). 
(3) The embryological method of Flechzig studies variations in 
cortical areas on the basis of the varying periods at which 
the axones acquire their medullary sheaths. 

It is not to be thought that these individual areas of the 
brain function as would separate units — 'the point of view held 
by the phrenologists Gall and Spurtzheim and their successors. 
When we refer to the superior convolution of the temporal lobe 
as the center for hearing, we mean that it is the focus of cortical 
activity produced by impulses from the VHIth nerve, for the 
brain is active as a whole and not in parts. Consciousness at 
any one moment contains elements whose neural accompani- 
ments are widely spread throughout the cortex. An interrup- 
tion of the association pathways from any primary sensory 



THE NERVOUS SYSTEM 



: •';•;•;?;•:/ 



i53 



J i u»* 





I f ffil 






«.',/! 



i|ii"|f 






Fig. 31. — Sections from the cerebral cortex (from Quain after Cajal). 
The sections reveal great variations in cell pattern. A is from the pre- 
Rolandic area. B is from the visual area of the occipital lobe. 



154 GENERAL PSYCHOLOGY 

center with the consequent partial isolation of it from the rest 
of the cortex leads, on the conscious side, to the loss of customary 
meanings that attach to objects, and is termed aphasia. One 
may see and hear normally when so afflicted, but one cannot 
understand or identify objects. 

The Cranial Nerves. — Twelve pairs of cranial nerves are 
given off from the brain, some of which are purely sensory, others 
purely motor, while others have both sensory and motor fibers. 
The points of origin from the external surface of the brain are 
shown in Fig. 25. These nerves are numbered from I to XII, 
beginning at the anterior end of the brain. The names and 
functions important for us to know at present are as follows: 

NO. NAME FUNCTION 

I Olfactory Smell 

II Optic Vision 

III Oculo-motor Motor and sensory to eye-muscles 

IV Trochlear Motor and sensory to eye-muscles 
V Trigeminous Sensory from skin, mouth, and 

teeth 

VI Abducens Motor and sensory to eye-muscles 

VII Facial Taste on anterior part of tongue 

VIII Auditory Hearing and equilibrium 

IX Glossopharyngeal Taste on back of tongue 

X Vagus Motor and sensory to viscera 

XI Spinal accessory 

XII Hypoglossal 

We shall study the functions of certain of these sensory nerves 
and their related receptors in much detail in the chapter on 
"Sensory Processes." 

Important Groups of Conduction Paths. — In order to make 
the foregoing account of the nervous system significant, it is 
necessary that the reader actually trace out the schematic 
pathways followed by nervous impulses in simple types of 
behavior. Suppose, for example, that I see an object, volun- 



THE NERVOUS SYSTEM 



155 



tarily reach for it with my right hand, and then a sensory impulse 
is started, part of which causes me reflexly to grasp the object 
and part of which reaches the cortex and accompanies the con- 




Fig. 32. — Probable pathway of a nerve impulse underlying a simple 
response. R, retina of eye; T, thalamus; 0, occipital lobe; PR, pre- 
Rolandic area; M', muscle; S, skin; sg, spinal ganglion; M, medulla; 
FR, fissure of Rolando. 



sciousness of touch. What is the neural pathway followed by 
these impulses? The impulse (Fig. 32) starts in the retina, 
goes to the thalamus, thence to the occipital lobe, and I see 
the object. The impulse now passes over an association neurone 



156 GENERAL PSYCHOLOGY 

to the pre-Rolandic area, whence another neurone carries it to 
the anterior horn of the spinal cord at the level of the hand. 
Another neurone carries it to the muscles of the hand, and X 
have touched the object. Stimulation of a sense-organ in the 
skin starts an impulse over a spinal sensory nerve which enters 
the dorsal horn of gray matter. Part of the impulse passes 
into a cell in the ventral horn of gray matter on the same side 
and goes back to the muscle of the hand, and I rerlexly seize the 
object. In the meantime part of the impulse has passed up 
the cord over one neurone and is then transferred to another 
in the medulla which carries it to the thalamus. From here a 
third neurone carries the impulse to the post-Rolandic area, and 
I am conscious of having touched the object. 

In this fashion the reader can trace out many probable 
paths over which nerve currents pass, conditioning particular 
instances of behavior. It is important to remember the follow- 
ing points, which have already been presented, in order to make 
the constructions with the least difficulty: (1) the names of 
the lobes of the brain and their functions must be memorized; 
(2) all sensory impulses pass through the thalamus, save certain 
olfactory ones; (3) all motor impulses conditioning voluntary 
action originate in the pre-Rolandic area; (4) association 
neurones connect any two or more parts of the cortex; and 
(5) in the spinal cord sensory impulses always enter on the 
dorsal side and motor impulses always go out from the ventral 
side. 

The hypothetical nervous activity diagrammed in this 
manner differs from what actually occurs largely in its greater 
simplicity. Many neurones are involved wherever one was 
mentioned above, and many associated neurones are active in 
the cortex, lending meaning to the conscious state where we 
have mentioned none. Wherever it is possible as our account 
of psychology proceeds we shall sketch the probable neural 



THE NERVOUS SYSTEM 157 

processes concerned in the different activities. The student 
must remember throughout his work to correlate of his own 
accord, so far as possible, neural activities with the various 
phenomena of psychic life. 



REFERENCES 

Bing, Robert. Compendium of Regional Diagnosis. Second edition. 

New York. 
Dunlap, Knight. Psychobiology. Baltimore: 1914. 
Herrick, C. J. Introduction to Neurology. Philadelphia: 191 5. 
Howell, W. H. Text-book of Physiology. Philadelphia: 1915. 
Lickley, J. D. The Nervous System. New York: 191 2. 
Morris' Anatomy. Part III. Philadelphia: 1907. 



CHAPTER III 

REFLEX ACTION AND INSTINCT 

Introduction. — We have encountered the terms reflex action 
and instinct in nearly every chapter that has preceded, for they 
stand as fundamental to any study of psychology. So far as 
the science is concerned with consciousness, we must recognize 
the part instinct plays in shaping motives of conduct, in deter- 
mining emotional experiences such as fear and anger, and above 
all in constituting the basic factor which influences the content 
of the focus of consciousness. So far as the science of psy- 
chology deals with behavior, we must recognize that the 
elementary units of all responses of the animal are reflexes. 
Learning, habit-formation, and voluntary action are all com- 
binations of these relatively simple forms of response. 

Starting with the conception which we developed in chap- 
ter ii of the nervous system's serving to co-ordinate sense-organs 
(receptors) and muscles and glands (effectors), we might con- 
tinue our study in either of two ways. We might start with 
sense-organ activities and follow through the topics of sensation, 
imagination, memory, and thought. Or we might begin on the 
motor side and work through the topics of reflex action, instinct, 
and habit, and then pass to the closely related topics of emotion 
and affections before taking up the sensory side. We have 
elected to follow this second plan for the reasons sketched in the 
paragraph above. 

Definition of Reflexes. — In the topic of reflex action we are 
to examine the elementary mechanics of action. All behavior 
is a combination more or less complex of -the relatively simple 
inherited activities of muscles and glands. Our brief examina- 
tion is therefore the necessary prologue to the understanding of 

158 



REFLEX ACTION AND INSTINCT 159 

instincts, habits, and intended (voluntary) actions. A reflex 
act is a simple inherited mode of response controlled by the nervous 
system. This definition rules out all responses of organisms 
devoid of nervous tissue. Such responses are tropisms. It 
also rules out those responses in animals with nervous systems 
where the activity is initiated directly by chemical means, as, 
for example, the case in man where the presence of pancreatic 
juice in the intestines stimulates the glands there to pour forth 
their secretions. These cases are also tropisms. From such 
statements it should be clear that reflex action is not a state of 
consciousness but a mode of muscular and glandular activity. 
The part that is inherited is the synaptic connection or resist- 
ance which finally determines the nature of behavior. Figure 25 
represents two reflex arcs. The motor neurones of one may 
be assumed to lead to the muscles that extend the hand and the 
other to lead to flexor muscles of the hand. The sensory neurone, 
which has synaptic connections with each motor neurone, comes 
from the skin, where it can be stimulated by a "painful" object. 
When such an object sets up a sensory nervous impulse, this 
impulse passes immediately out over the former of the two neu- 
rones by virtue of the relatively low resistance of this synapse, 
and the injurious object is dropped. It is this low resistance at 
the synapse which is inherited. Even in the extremely simple 
case that we have taken, however, the activity is not confined to 
one reflex arc. No one reflex arc acts independent of the other 
reflex arcs. In our present instance, before the hand could be 
opened (extended), the muscles which closed (flexed) it had to 
relax. In other words, the sensory impulse not only excited 
one group of muscles; it also inhibited the antagonistic group. 
Even the simplest activity therefore involves a co-ordination 
of reflex arcs. The mechanism of inhibiting muscle F is as 
much inherited as that for exciting muscle E. It is primarily 
for this reason that no sharp distinction can be drawn between 
reflex action and instinct. Other reasons we shall canvass later. 



160 GENERAL PSYCHOLOGY 

The reader should not infer from the preceding description 
that all reflexes occur through the spinal cord. The brain is 
particularly rich in reflex centers. Two important ones were 
noted in chapter ii, the medulla and the mid-brain. 

Types of Reflexes. — It is customary to distinguish two 
main classes of reflex action, physiological reflexes and con- 
scious reflexes. Consciousness never plays a guiding or deter- 
mining role in reflex action. To the person who experiences 
the reflex, consciousness even seems to be an onlooker. It 
does, however, accompany many reflexes, the ones of the second 
class mentioned above. We are never directly conscious of 
the muscular contractions in physiological reflexes, i.e., we 
never feel the iris of the eye or the muscles of the heart contract. 
On the other hand we may be aware of ,the contraction of the 
muscles in sneezing, swallowing, or winking by attending to 
these activities. It should be noted that in the case of most 
conscious reflexes we are able to duplicate them voluntarily 
more or less accurately. We may wink or swallow voluntarily. 
It is important, however, to observe the fact that not only in 
this case is the performance more awkward and tiring, but it 
also has accompanying it a feeling of strain and effort (active 
participation) which is absent when the response is reflex. 
Physiological reflexes we are aware of only indirectly through 
their effects. We notice, for example, the clearing up of vision 
due to the focusing of the eyes (contractions of the iris and of 
the ciliary muscles which regulate the lens), or we may attend 
to the beating of the heart against the walls of the chest; but 
we are not conscious of the muscular actions themselves. 
Reflexes may also be classified as conditioned and unconditioned 
and as allied and antagonistic. The two former classes were 
discussed in the chapter on "Animal. Psychology." Allied 
reflexes are those which occur simultaneously and facilitate 
each other. A dog starting to scratch, e.g., must shift his 
weight to three legs. The reflexes so involved are "allied" in 



REFLEX ACTION AND INSTINCT 161 

relation to the scratch reflex. Antagonistic reflexes are those 
which cannot occur simultaneously and which inhibit each 
other. Walking and running are two cases. The activities 
of paired flexor or extensor muscles form another example, 
i.e., one cannot extend his fingers at the same moment that he 
is grasping something with them. A clearer view of the sub- 
ject can be gotten from a survey of the experimental work on 
this topic. 

Typical Phenomena in Reflex Action. — Most of the experi- 
mental data that we have on the simpler reflexes come from a 
study of spinal animals. A spinal dog, e.g., is one whose spinal 
cord has been transected, or cut across, just below the medulla, 
thus freeing the reflex activities controlled by the cord from 
the influence of the brain. In animals like the dog the reflex 
functions of the cord persist unimpaired by the operation. In 
the dog the scratch reflex has been most thoroughly studied 
(Sherrington). If any point in the saddle-shaped area of the 
spinal dog shown in Fig. 33 is stimulated, the hind leg on that 
side is alternately flexed and extended in the typical scratch 
activity. Only allied harmonious reflexes are active at any one 
moment. The rhythm or rate of this reflex is constant (4.5 
beats per second) no matter what the intensity of the stimulus. 
The scratch rhythm proceeds practically unmodified by varia- 
tion of the rhythm of the stimulation of the skin. This partly 
depends on the fact that each reflex has a refractory period during 
which, even apart from fatigue, it cannot be fully re-excited. 
The refractory phase is very similar to inhibition and in the case 
of the scratch reflex depends upon changes in the central portion 
of the reflex arc. If the intensity of the stated stimulus is 
gradually increased, the phenomenon of spread occurs, i.e., 
more and more reflexes are aroused, due to the irradiation of 
the nervous impulses in the cord, until the whole dog is active. 
Furthermore, if two points of the saddle-shaped area are stimu- 
lated simultaneously, each stimulus by itself being too weak to 



l62 



GENERAL PSYCHOLOGY 



arouse a response, the reflex will nevertheless appear as a result 
of the summation of the nervous impulses. Other additional 
facts have been brought out that are of importance in securing 
a comprehensive view of the behavior mechanism. Each 
reflex, for instance, has a latent time, i.e., a period intervening 
between the application of the stimulus and the appearance of 
the response. The length of this latent time will vary from 




Fig. 33. — A spinal dog. The figure also indicates reflex arcs from the 
point x in the saddle-shaped area to the flexor (F) and extensor (E) mus- 
cles of the leg. The approximate location of the spinal section is shown in 
the cervical region (S). 



.022 to .2 second, depending on the intensity of the stimula- 
tion. Sherrington has found that a reflex arc is just as ready 
to conduct, i.e., it responds as quickly, when it is inactive as 
when it is active at the moment of stimulation. Fatigue also 
influences reflex activity. Again, other things being equal, the 
protective reflexes — those aroused by injurious or noxious 
stimuli — have the right of way over other reflexes. At any 



REFLEX ACTION AND INSTINCT 163 

one moment, for example, contact with the floor tends to 
arouse the reflexes in the dog which give him his upright 
position. A painful stimulus breaking in upon this immedi- 
ately gets control of the muscles of the leg and produces a 
protective reflex activity. 

Resulting View of Behavior. — On the basis of these observa- 
tions, how are we to describe the behavior of the dog or other 
animal at any one moment? Each animal has a definite limited 
number of muscles supplied by a limited number of motor 
nerves. All types of behavior, all forms of action, must use 
this single motor system. At any one moment eyes, ears, nose, 
and skin are sending sensory impulses in to the central nervous 
system. Here they must compete for the control of the motor 
system. Which impulse shall win out will depend upon the 
interrelation of the factors we have just mentioned: refractory 
period, spread, summation of stimuli, latent time, fatigue, 
inhibition and facilitation, and the "right of way." A slight 
variation in any one of these factors may be sufficient to give 
vision control of the muscles as opposed to audition. In this 
case the animal responds to what he sees as opposed to what he 
hears. This selection and determination of behavior are finally 
decided at the synapse on the basis of varying resistances to the 
passage of competing nervous impulses. This determination 
of behavior by synaptic connections we shall find exemplified in 
our present topic, "Instinct." 

Definition of Instincts. — An instinct is an inherited 
co-ordination of reflexes. Like the term reflex, it refers not to a 
state of consciousness but to a mode of behavior. The two 
forms of inherited response shade into each other with com- 
plexity the chief difference. Popularly the term instinct — 
fear, anger, etc. — is applied to those particular inherited 
responses which are so well defined and prominent in the life of 
the individual as to attract attention. Many technical distinc- 
tions have been offered, none of which, however, have served 



1 64 GENERAL PSYCHOLOGY 

to differentiate completely the two modes of action. Con- 
sciousness, for example, cannot be made the point of difference, 
for it frequently accompanies reflex action, e.g., in the conscious 
reflexes we have discussed. The fact that instincts have "an 
end in view" has been given as the dividing principle, but we 
are equally as well aware of the purpose of winking as a defense 
measure as we are of that of the more complex behavior in 
anger. It is occasionally urged that instincts differ from reflex 
actions in that the former are accompanied by emotions while 
the latter are not. This criterion is inadequate because many 
instincts like play and food-getting have no emotions which 
invariably accompany them in the way that fear accompanies 
the instinct of flight and anger the instinct of pugnacity. 

When we refer to instinct as an inherited co-ordination of 
reflexes, we are stressing the fact that what is inherited is the 
particular combination of reflexes. Anger in a man, if uncon- 
trolled, involves the clenching of the fists, a threatening attitude, 
and changes in the facial muscles, in breathing, and in the heart- 
rate. If one strikes, that act is the stimulus for the next blow, 
and in this way a regular chain of activity is set up char- 
acteristic of the species. When we speak of the inherited 
co-ordination of reflexes in a bird, we may have in mind the 
following performance in nesting: The bird picks up a straw, 
flies to a limb, deposits it, and returns for another. This is 
repeated until several straws are accumulated, whereupon 
arrival at the nest causes the bird to execute certain turning 
movements by means of which the nest is shaped. The com- 
pletion of the nest stimulates the egg-laying mechanism. The 
presence of eggs leads to brooding. In a similar manner we 
might trace other co-ordinations of reflex actions which are 
characteristic of birds of a given class. 

In any particular case the only criteria for determining 
whether an act is an instinct or not are: (i) the relative perfec- 
tion of the response on its first appearance, and (2) the uni- 



REFLEX ACTION AND INSTINCT 165 

versality of the response among members of the same species. 
These criteria enable us to pick out the instincts from such a 
list of activities as: typewriting, swimming, tennis-playing, 
nest-building, honeycomb-making, the killing of mice by kittens, 
the provisioning of the nest by wasps, the singing of birds, 
the pecking of chicks, etc. From this list we can at once discard 
typewriting and tennis-playing. Neither of these forms of 
response appears at the start full-grown, but each is built up 
by experience. Neither, moreover, is characteristic of all mem- 
bers of any species. With swimming we hesitate. Probably 
all people and all animals of certain species when in water over 
their depth execute certain characteristic swimming or flounder- 
ing movements. To this extent we have an instinct — an 
inherited form of behavior. To the extent that the swimming 
is not perfect but is improved with practice we have not an 
instinct but a habit. Which of these terms we shall apply, 
instinct or habit, depends upon the relative amount contributed 
to the response by heredity and by experience. Many of the 
above responses are instinctive — nest-building, honeycomb- 
making, the pecking of chicks, etc. By this we do not mean 
that they are uninfluenced by experience or that they appear 
in unvarying form ; we only mean that the inherited character- 
istic predominates. The following description of experimental 
data on instincts will serve further to clarify this point. 

Some Experimental Studies of Instinct. — Practically all 
studies of instincts, in the popular sense of that term, have been 
made upon animals. (We should not forget, however, that 
breathing and circulation are instincts in the technical sense 
of that term and that these have been extensively studied in 
man.) There are two chief reasons for this: (1) animals are 
more readily controlled from birth and so make more convenient 
study material, and (2) man's responses are so deeply influenced 
by custom and habit that it is a rare instance when an instinctive 
response breaks through in anything like its original form and 



166 GENERAL PSYCHOLOGY 

vigor. This last fact is put to particular use in psychoanalysis, 
as we have already seen. In addition it has given rise to two 
contradictory statements. One is that man has more instincts 
than animals and that their interference is what gives the highly 
varied aspect to his behavior (James). The other is that man 
has no instincts in the true sense of the word (Thorndike) . The 
former view is probably much nearer the truth. 

i. The Pecking of Chicks. — A good example of this experi- 
mental work is the analysis of the pecking instinct in chicks, 
published in 191 1 by Breed. He undertook the problem in 
order to determine from the study of a simple, easily controlled 
response how perfect a particular instinct is at its first appear- 
ance and just how much development takes place after the 
first performance. The pecking response (the terminology 
of Spalding and Morgan being followed) was divided into 
three parts: striking, seizing, and swallowing. The chicks 
were hatched in an incubator and then kept in a dark basket 
prior to the tests. By this method no opportunity was afforded 
the chick for practice outside of the tests. For the test the 
chick was placed upon a smooth black table-top upon which 
were a few grains of wheat. In pecking the chick might miss 
the grain; or strike it, but not seize it; or seize it, but not 
swallow it; or success might crown its efforts and the grain be 
swallowed. Fifty trials were given each day. Figure 34 shows 
how the chicks progressed from day to day. Curves 1, 2, 3 
show the decrease in error with increase in age, while curve 4 
shows the increase in perfection with age. We may thus see 
graphically that the chicks, starting out with only 15 per cent 
of the responses perfect, reached an average of 84 per cent. 
Not all of this remarkable increase in efficiency, however, is to be 
credited to practice or habit, as one might suppose at first 
thought. Undoubtedly as the chick grows older the nerve 
centers (synaptic connections) which control the instinct are 
maturing so that part of the increase in efficiency is due to the 



REFLEX ACTION AND INSTINCT 



167 



growth of the instinct as a result of strictly inherited tendencies. 
This has been tested and proved the case by Shepard and Breed 
(19 14). Figure 35 shows the results. Chicks were kept from 
pecking for various intervals, some for three days, some for 



Trials 











































































































IV , 


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Oay9 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 

Fig. 34.— Graphic records of data secured by Breed in his study of 
the pecking instinct of chicks. The figure is described in the text. 




DAYS 



Fig. 35. — The development of the pecking instinct with normal con- 
ditions (S) and after delays of 3 days (I and III), after 4 days (IV), and 
after 5 days (V). S is based upon 21 chicks; I, upon 4; III, upon 6; IV, 
upon 3; and V, upon 1 (from Shepard and Breed). 



1 68 GENERAL PSYCHOLOGY 

four days, and some for five days, and were then tested. All 
chicks so delayed began below normal accuracy, but caught up 
to normal accuracy after two days' practice. This unusually 
rapid increase in accuracy during the first two days is made 
possible by the increased maturation of the nerve centers. 1 We 
have gone thus into detail in this experiment because, inadequate 
as it may be, it is one of the most accurate and quantitative 
studies that we have of instinct. This study and similar ones 
can tell us more than volume upon volume of speculation con- 
cerning the activities of animals. 

2. The Instinct for Vocalization in Birds. — Studies by 
Yerkes and Bloomfield on the instinct to kill in kittens have 
indicated that certain inherited synaptic connections function 
independent of imitation and social example. In the follow- 
ing study by Conradi (1905), on the other hand, we find an 
equally certain case of instinctive activity and an equally 
certain influence of social forces (the stimulation of the bird by 
the songs of its associates) on the development of this activity. 
From this study and from that of Scott and Witchell it seems 
certain, moreover, that the call notes of birds are the primitive 
vocalizations, and are more uniformly inherited than the tend- 
ency to sing, which is present in addition in many birds. The 
tendency toward vocalization is inherited, but in what guise 
this tendency shall appear is determined largely by environ- 
ment. This is illustrated by the fact ascertained by Scott 
that Baltimore orioles when kept alone and free from other 
birds developed a novel song of their own rather than the song 
characteristic of their species. Conradi's work illustrates the 
same point. He secured some young sparrows from the wild 
and placed them either under the care of a mother canary or 
in the room with canaries. Some developed the sparrow call 
note, and in addition all learned more or less thoroughly the 

I This interpretative statement varies from that made by Shepard 
and Breed. 



REFLEX ACTION AND INSTINCT 169 

songs of the canaries with whom alone they all associated. I 
may quote one observation: 

On September 26, when the sparrow was a little over three 
months old, he was for the first time observed to give a trill. It was 
short and musical and was given a number of times in succession. 
These short trills were at first only rare but they increased in frequency 
during the year. When he gave them he would sit still on his perch 
and give them one after another very modestly. Now (Dec, 1904), 
he gives short trills interspersed with other notes, punctuating the 
whole by turning complete circles and semi-circles on his perch. 

None of these sparrows ever had the characteristic call note of 
the wild species, but by and by adopted those of the canary. They 
imitated the canary perfectly except that their voice did not have the 
musical finish. 1 

When removed from the canary environment they soon lost 
the canary song, but reacquired it on being again placed with 
those birds. 

The Permanent Character of Instincts. — -In spite of frequent 
opinions expressed to the contrary, there is no clear evidence 
that instincts in man and the higher animals are "intrinsically 
transitory" — to use James's term. Not all instincts are present 
at birth. Breathing, sucking, swallowing, fear (possibly), and 
others are, it is true; but many appear later, with the sex and 
parental instincts coming last. Once these forms of behavior 
have appeared, however, once the nerve centers which control 
them have matured, there is no good reason to believe that the 
organism ever loses them. Many instincts of infancy and 
childhood, such as sucking and playing, may be suppressed or 
transformed and hence be apparently absent in later life. In 
many cases, however, the behavior will appear upon representa- 
tion of the proper stimulus, and in other cases the instinct will be 
found active as an integral part of some other form of behavior. 

1 E. Conradi. "Song and Call Notes of English Sparrows when 
Reared by Canaries," Amer. Jour. Psych., XVI (1905), 197. 



170 GENERAL PSYCHOLOGY 

The Modification of Instincts. — Most if not all instincts are 
variable and not strictly rigid and mechanical. Probably none 
run their course in the same manner time after time. Much of 
this variability of inherited forms of behavior — which has been 
found even in the Protozoa — is due to internal physiological 
conditions of a temporary nature, i.e., fatigue, satiety, etc., 
which modify, or for the moment inhibit, all or part of the 
instinct. Variability, however, as found in those animals that 
profit by experience, is a matter also of permanent status. The 
basis of whatever variability there may be is to be found in the 
changed condition of the synapses controlling the final motor 
pathways to the muscles and glands. Inasmuch as instincts 
depend upon the proper functioning of total reflex arcs, the 
modification of instinct may occur either on the sensory 
(stimulus) side or on the motor (response) side, or on both. 
In each case the process is one of learning and habit-formation. 
Modification on the sensory side is illustrated by the fact that 
at one period of life I may fear "being on high places/ 5 while 
at a later period this stimulus no longer arouses fear. Or the 
situation may be the reverse. Objects that I do not fear at one 
period may come to arouse intense fear by virtue of my experi- 
ence with them. On the motor side the instinct is modified 
by experience so that at one period of life anger, for example, 
is expressed in quite a different manner from that of its later 
form. The modification need not be, but often is, in the form 
of total inhibition of external movements. And in some indi- 
viduals the "control" of instinct may be so thorough that no 
stimuli met in the ordinary course of events can call forth a 
visible disturbance like anger or fear, or even arouse internal 
disturbance that can be felt. Such a person may be termed 
"cold-blooded," "unsympathetic," and the like. 

As the last statement implies, the facts of the last paragraph 
are of tremendous social and individual import. Because other 
peoples or classes do not respond to the same objects as we, we 



REFLEX ACTION AND INSTINCT 171 

ordinarily tend to deny that they possess the power to respond. 
The fact that a savage does not react with the instinct of shame 
at the absence of clothes does not mean that the instinct is 
lacking. As new customs arise, new stimuli take the place of 
the old in arousing instincts. Ribot and McDougall have well 
pointed out these facts. What arouses admiration or love in 
one class may arouse disgust in another. The whole process 
of educating (in the broad sense) and socializing an individual 
consists in determining for him, and in training him to accept, 
the approved stimuli for instinctive responses. With develop- 
ment the instinct may be set off by more and more subtle 
stimuli. (This is the same principle exemplified by the con- 
ditioned reflex of an earlier chapter, p. 16.) It does not 
take actual bodily injury to make one angry, for one may grow 
angry at an insult, at an attack on one's friend's honor, at a 
criticism of one's ideals. The ability to react to these more 
subtle stimuli makes one of the chief differences between man 
and animals and between man and man. The animal's instinct 
of anger and defense has only sensory stimuli, while man's 
instinct has in addition the stimulus of ideas representing the 
foregoing abstract relationships or values. Holt refers to this 
increasing abstractness as the "recession of the stimulus." The 
hope of a democratic social group lies in the ability of the ma- 
jority to react to these less obvious stimuli as well as to the 
more obvious; that is, the average man must react with anger, 
if personal, national, or international ideals are threatened, as 
effectively, if not as readily, as when his bodily well-being is 
attacked by a visible opponent. One great function of a leader 
is to call the attention of his followers to the presence of such 
an "invisible" stimulus to the instincts. 

The Origin of Instinct.— Theories as to the origin of instinct 
attempt to reconstruct the process by which in the past history 
of the race such co-ordinations of reflexes have appeared. When 
once all or part of the form of behavior has appeared in a given 



172 GENERAL PSYCHOLOGY 

animal, its transmission to subsequent generations is a question 
of heredity. As such it is a topic for genetics and is subject 
to the laws that govern the transmission of any structure. A 
connection of neurones, such as underlies fear or anger, is just 
as much a structure as is the color of the eyes, the existence of 
the nose, muscles, etc. Each individual inherits sense-organs 
and muscles which are essentially like those of his parents. 
Sense-organs and muscles are "pure lines," homozygous char- 
acters, and breed true. If an individual born with one eye (not 
as the result of accident, but of germinal variation) were crossed 
with another born with two eyes, the result would undoubtedly 
be similar to the case of inheritance of eye-color. Here, if 
parents have different eye-colors, the offspring of the first 
generation (F x ) all have a single color — 'Called the dominant 
color. With respect to color they are hybrids. If these indi- 
viduals interbreed, the next generation (F 2 ) will be some pure 
brown-eyed, i.e., the dominant trait, some mixed, and others 
pure recessive, i.e., blue-eyed. This form of inheritance is 
termed Mendelian. The union of the pure dominant or the 
pure recessive with a similar individual will result in pure 
progeny with respect to the trait in question. There is every 
reason to believe that if an animal should be found minus the 
instinct (structure in nervous system) of fear and could be 
crossed with an animal in whom the instinct was present, the 
progeny in the F 2 generation would show the typical Mendelian 
segregation as indicated above for eye-color. Yerkes has in 
fact performed tests of this type upon the inheritance of the 
instincts of savageness and wildness in rats, securing evidence 
for the foregoing type of inheritance. 

Before an instinct so complex as fear can appear, certain 
sense-organs, muscles, and reflex arcs must already have 
appeared. The appearance of fear adds to this the structural 
fact of a certain kind of co-ordination. We have already seen 
that no distinction can be clearly drawn between reflexes and 



REFLEX ACTION AND INSTINCT 173 

instincts. There is no reason, therefore, to separate the 
question of the origin of one from that of the origin of the 
other. This, however, is just what the theories of the origin 
of instinct tend to do. When a receptor or an effector appears 
in the history of the race, it has a function. If this function 
(muscular contraction or glandular secretion) is controlled by 
the nervous system, the function is a reflex (or an instinct). 
The first appearance of any structure and the first appearance 
of any inheritable variations in it are both termed chance 
variations, or "sports." Those which are either useful or at 
least not particularly harmful survive and become permanent 
characteristics of the species (by the action of natural selection). 
Historical Theories of the Origin of Instinct. — -Three 
important theories for the origin of instinct have been proposed. 
(1) The lapsed-intelligence theory of Cope and Wundt holds that 
originally instinctive acts were performed consciously and 
voluntarily; that by repetition they became habitual; and 
that they were then inherited by the next generation as instincts. 
This theory is based on the assumption that acquired character- 
istics — habits, strength of arm, etc. — can be transmitted by 
heredity. General biological opinion, however, is against this 
belief. The theory would further lead us to assume a high 
grade of intelligence (consciousness) in lower animals, a supposi- 
tion which is contrary to experimental fact. The error of the 
theory is a result of reading into animal life the known fact that 
in human experience acts performed consciously are later 
executed habitually and automatically. (2) The reflex theory 
of Spencer holds that the reflexes which make up a given instinct 
appear one by one, due to chance variations (sports), until the 
whole instinct is present. This supposition is in essential 
harmony with the point of view of the last section. The theory 
has been criticized because it is claimed that the individual 
reflexes are only valuable as parts of the whole, and by them- 
selves cannot adjust the organism to its environment in such 



174 GENERAL PSYCHOLOGY 

a way as to aid in its survival. Why should a bird pick up 
straws or weave, it is asked, e.g., unless the whole nest-building 
instinct is present? The answer is clear. What appears first 
as a chance variation is the fundamental feature of nesting, 
staying near the eggs or actually hovering over them (Whitman) . 
To this fundamental behavior other elements (digging a depres- 
sion, collecting straws, etc.) are added by further chance varia- 
tions. These additional variations may not be necessary for 
survival (witness the great variations in nest structure), but 
they may pave the way for, as well as follow after, more com- 
plex modes of life. (3) The organic-selection theory of Osborne, 
Baldwin, and Morgan attempts to remedy the supposed 
deficiences in the Spencer theory by combining it with certain 
aspects of the lapsed-intelligence theory. During the period 
of the imperfect and growing instinct the animal solves its 
problems partly by intelligence and accordingly survives. 
These intelligent variations are not inherited, but must be 
made anew by each generation. The point is important, but 
it hardly deserves to be ranked as a separate theory. It calls 
attention to the fact that habit-formation is a characteristic 
of all (most) animals and aids in survival, for there is no doubt 
that without it many or all species would perish. It does not, 
however, account for the appearance of an instinct in one group 
and not in another save by the assumption of unequal learning 
abilities. Each of the three theories, however, is important 
for our study because, by laying special emphasis upon different 
points, they aid us in getting a more comprehensive view of the 
whole question. 

The Classification of Instincts. — Many classifications of 
instincts have been proposed, but we know too little as yet about 
the subject to formulate a very fruitful system. What is 
particularly needed is a thorough knowledge of the exact stimuli 
which set off the various instincts and of the exact effector 
activities involved. One of the best classifications is that sug- 



REFLEX ACTION AND INSTINCT 175 

gested by Marshall on the basis of function. Instincts which 
function for the preservation of the individual form the first 
class. Here belong fear, anger, food-getting, curiosity, walk- 
ing, standing, etc. In the second class he places instincts 
which function for the preservation of the race. This would 
include sex and courtship instincts and the parental instinct. 
A third class includes instincts which function for the pres- 
ervation of the social group. The most important ones are 
rivalry, constructiveness, acquisitiveness, and gregariousness. 
Until further extended rigorous experimental observation 
can make clear the detailed nature of the various instincts, 
we must be content with this brief mention of the problem of 
classification. 

Instinct and Intelligence. — From our extended account of 
instinct, one must not conclude that it is a separate and distinct 
type of behavior. We have already seen its intimate relation- 
ship to reflex actions and are now to consider it in connection 
with intelligence. The popular mind assigns a preponderance 
of instinct to the animals and retains intelligence for man. If 
we use the term intelligence as synonymous with "thinking," 
that view is undoubtably correct. In the better sense of the 
term, however, we mean adaptive and variable behavior. To 
the extent that responses are determined by heredity, they are 
instincts; to the extent that they are modifiable within the 
animal's individual experience, they are intelligent. Instinct 
and intelligence, then, go hand in hand through the animal 
series. Myers has made the curious mistake of regarding 
instinct as the objective and intelligence as the subjective 
(conscious) side of behavior. This view, however, ignores the 
fact that modes of behavior differ genetically in that some are 
largely inherited and others are largely acquired. The terms 
instinct and intelligence are probably the best ones to designate 
this difference, although, as we have seen, no hard-and-fast line 
can be drawn to separate the two types of behavior. 



176 GENERAL PSYCHOLOGY 

Habit. — Habits as well as reflexes and instincts are modes 
of response and therefore are entitled to a place in the present 
chapter. Habits are acquired co-ordinations of reflexes. They 
differ from both reflexes and instincts in their acquired character, 
and in addition they are more complex than the former. An 
illustration will serve to make this clearer. Writing is a mode 
of muscular response which depends upon the proper adjust- 
ment and co-ordination of the reflexes of the hand and arm. 
Individuals do not develop this capacity for response without 
training, although the movements of the specific muscles appear 
early in childhood. Therefore writing cannot be an instinct, 
but is clearly a habit. Its elemental parts, as reflexes, are 
inherited; but the harmonious relationship of these, which is the 
essential characteristic of the response, is acquired. Contrast 
the situation with that of an instinct. Instincts, too, are com- 
posed of elemental reflexes, and inasmuch as they are modified 
by experience include phases that may be termed habits (intelli- 
gence) . Yet however much fear or anger may be modified, the 
essential dominating characteristic of the mode of adjustment 
is still hereditary, and we term the response an instinct. The 
distinction between these two types of responses is a behavior- 
istic, not a conscious, one. It makes no difference, as a rule, in 
the "feel," or consciousness, of a series of muscular responses 
whether they are essentially inherited or acquired. A sneeze 
would give rise to the same state of consciousness if it were a 
habit and not a reflex or instinct. We may point out, however, 
two ways in which consciousness may at times vary, depending 
upon the acquired or non-acquired character of the muscular 
and glandular activities underlying it. (1) Some instincts are 
more impulsive, more compelling, more irresistible, than any 
non-instincts ever are. No acquired response could approxi- 
mate the impulsive character of a panicky fear or a blind rage. 
(2) Occasionally one finds a group or co-ordination of reflexes 
involving particularly the viscera (inner organs of the body) 



REFLEX ACTION AND INSTINCT 177 

where activity is invariably followed in consciousness by an 
experience termed emotion. Habits may enter in and modify 
these responses, but habits (acquired modes of response) never 
form the core of activity characteristic of the emotional seizure. 
A detailed account of emotions will be given in the following 
chapter. 

The two problems of importance in the study of habit are: 
(1) What is the process of habit-formation and what are the 
laws governing it? (2) What are the nature and function of 
habit when its growth is completed? The latter problem we 
have discussed already, partly in the chapter on " Social Psy- 
chology" in connection with custom, and partly in the present 
account where the modification of instincts has been involved. 
The final summary of habit-formation must come in the chap- 
ter on "Memory," for the problem is one and the same with 
that of learning. To acquire a habit is to learn, and to learn 
js_lo_jnemorize. When that topic is taken up it will be well, 
therefore, to reconstruct as well as one may the view of habit 
as an acquired co-ordination of reflex responses. For the 
present, however, we must turn our attention to the closely 
related topic of emotion. 

REFERENCES 

Breed, F. S. "The Development of Certain Instincts and Habits in 

Chicks," Behav. Mon., I (1911), No. 1. 
Conradi, E. "Song and Call Notes of English Sparrows when 

Reared by Canaries," Amer. Jour. Psych., XVI (1905), 190-98. 
James, William. Principles of Psychology, Vol. I, chap, iv; Vol. II, 

chap. xxiv. New York: 1890. 
McDougal, William. An Introduction to Social Psychology. Fourth 

edition. Boston: 191 1. 
Scott, W. E. D. Articles on song birds found in Science, XIV, XV, 

XIX (1901-4). 
Sherrington, C. S. The Integrative Action of the Nervous System. 

New York: 1906. 



178 GENERAL PSYCHOLOGY 

Shepard, J. F., and Breed, F. S. "Maturation and Use in the 
Development of an Instinct," Jour. Animal Behav., Ill (1913), 
274. 

Thorndike, E. L. The Original Nature of Man. New York: 1913. 

Watson, J. B. Behavior, chaps, iv and v. New York: 1914. 

Watson, J. B., and Lashley, K. S. "An Historical and Experimental 
Study of Homing," Carnegie Institution Publication, No. 211, 

IQI5- 
Yerkes, R. M., and Bloomfield, D. "Do Kittens Instinctively Kill 
Mice?" Psych. Bull., VII (1910), 253. 



CHAPTER IV 

THE EMOTIONS 

Introduction. — With the study of emotions we come back 
to the question of states of consciousness. The close connec- 
tion between instinct and emotions has already been implied 
in the terms that we used in the preceding chapter, for such 
terms as fear, anger, and love apply both to ways of acting and 
to ways of feeling. In both cases we are talking about unlearned 
processes. In each we have a fundamental, primitive, impul- 
sive, and almost irresistible fact. Both tend to carry one out 
of the ordinary modes of response and feeling and beyond the 
pale of social restraint. Vigorous anger tempts one to throw 
caution to the winds, and the passions of intertribal hate reveal 
only too well the thinness of the veneer with which custom, 
tradition, and thought have covered over the original modes 
of behavior suited to an earlier habitat. The delineation of 
emotion in human life has always been the peculiar task of the 
poet and the narrator. It is to these, and to his own experience, 
that the reader must turn for the first-hand data on the emotions. 
Our own account in the present chapter will be analytical, not 
humanly descriptive. In defining emotion we may either 
analyze it into its elementary components (i.e., give a structural 
definition) or we may state its function. But one cannot say what 
an emotion is without plunging at once into the theories of emo- 
tion. Accordingly, we can best orient ourselves in the whole topic 
by considering critically the James-Lange theory or definition. 

The James-Lange Theory of Emotion. — The conventional 
theory of emotion prior to 1884 when James 1 published his 

1 Lange wrote in 1885 and differs from James chiefly in considering the 
circulatory changes as the fundamental bodily disturbance in emotions. 

179 



180 GENERAL PSYCHOLOGY 

account in the British periodical Mind was much the same as 
the lay notion of today. I see an object about to strike me; 
I am frightened and run. The running is an instinct which 
seems to express the emotion that precedes it. This older 
theory would insist that the neural basis of emotion is an excite- 
ment in the cerebral cortex aroused directly from the brain 
center connected with the sense-organ that has been stimulated. 
For James and Lange, however, I see the object, run, and then 
I am frightened. To quote James: 

Common sense says, we lose our fortune, are sorry and weep; 
we meet a bear, are frightened and run; we are insulted by a rival, 
are angry and strike. The hypothesis here to be defended says that 
this order of sequence is incorrect, that the one mental state is not 
immediately induced by the other, that the bodily manifestations 
must first be interposed between, and that the more rational state- 
ment is that we feel sorry because we cry, angry because we strike, 
afraid because we tremble, and not that we cry, strike, or tremble, 
because we are sorry, angry, or fearful, as the case may be. Without 
the bodily states following on the perception, the latter would be 
purely cognitive in form, pale, colorless, destitute of emotional 
warmth. We might then see the bear, and judge it best to run, 
receive the insult and deem it right to strike, but we should not 
actually feel afraid or angry. 1 

For James and Lange the consciousness of the organic dis- 
turbances is the emotion, " .... the bodily changes follow 
directly the perception of the exciting fact, and .... our feel- 
ing of the same changes as they occur is the emotion." Thus 
on the James-Lange theory the nervous impulse passes to the 
viscera and to the body muscles before reaching the brain as 
a condition of emotion. This problem of the neural basis of 
emotion we shall discuss in detail in a later paragraph. 

This theory is exceedingly paradoxical, and it was made 
particularly so by the manner of its presentation. During the 

1 William James. Principles of Psychology (New York: 1890), II, 
449-5o. 



THE EMOTIONS 181 

years that immediately followed its publication bitter criticism 
was directed against it. To what extent one shall subscribe 
to the theory even now will depend upon how one understands 
it. There are two interpretations current: (i) The conscious- 
ness of the organic disturbances involved in instinct is the 
essential element in emotion, and serves to mark it off from other 
states of consciousness which are non-emotional. (2) Emotion 
is nothing but the consciousness of the organic disturbances 
involved in instinct. It is absolutely necessary to keep these 
two possibilities clearly in mind. The theory should be under- 
stood as James meant it, of course, and in an article published 
in 1894 he makes clear that he had in mind the first of the fore- 
going interpretations. Our first quotation above indicated this 
also, for there James is saying that unless the organic disturb- 
ances are present the experience (perception) is non-emotional 
and cold. It is not even essential to the James-Lange theory 
that one distinguish between one emotion and another on the 
basis of different organic accompaniments. It may well be 
that they serve to distinguish the emotion from the non-emotion, 
but not one emotion from another. Failure to hold these points 
clearly in mind has caused much confusion among the theory's 
critics. 

Even a casual inspection of the various emotions of daily 
life offers much evidence in support of the theory. Anger, if it 
does not involve a general muscular tenseness, a tendency to 
attack, a rapid heart-beat, and an increased respiratory rate, 
is hardly anger. As James says, if we take anger or fear or 
any other emotion and mentally abstract from it all the bodily 
disturbances or organic resonances, no emotion is left. One 
may then see the offending object, perceive the dangerous 
situation, but fear not. It is to be understood that many, if 
not most, of the bodily activities which characterize emotions 
manifest themselves internally. The individual is specifically 
aware of few of these visceral changes, i.e., he does not notice, 



182 GENERAL PSYCHOLOGY 

perhaps, the heightened respiration, the change in the distribu- 
tion of the blood, etc. Yet any or all of these bodily changes 
may change the whole quality of consciousness, just as we find 
to be the case in indigestion. Here one need not be specially 
aware of this, that, or the other bodily process, but he is vividly 
aware of general distress. From our last chapter we know that 
certain stimuli can arouse special muscular and glandular 
responses, due to synaptic connections set by heredity. If one 
is aware of the moving muscles, it is because sense-organs are 
located in or near them and are stimulated by the movement. 
The result is the passing of sensory impulses to the brain, and 
we become aware of the activity. We also know that to the 
extent the response is inherited, to that extent it is essentially 
uniform from one individual to another. The contraction of 
the pupil of the eye is the same in all people because the mecha- 
nism which controls it is the same. In a similar manner the 
fundamental quality of fear is the same in all persons, for under- 
lying this sameness in the conscious states is a form of nervous 
activity which is alike in all individuals. Furthermore we 
must remember that the reflex action involved is complex, not 
simple. It is important that we bear these facts in mind in the 
following sections as we consider the criticisms waged against 
this view of the nature of emotion. 

Criticism of the James-Lange Theory. — The consideration 
of the criticisms of this theory is a particularly valuable method 
of bringing out the various characteristics of emotional con- 
sciousness. We shall analyze these objections one by one. 
(i) It does not follow because an emotion cannot be imagined 
devoid of organic disturbances that the emotion is nothing 
but a consciousness of these changes. One cannot see color 
without extension or have a kingdom without a king; yet color 
is not extension, nor is a kingdom but a king. This criticism 
states the truth. Emotion is more than the consciousness of 
kinaesthetic, cutaneous, and organic sensations reflexly aroused. 



THE EMOTIONS 183 

It is also pleasant or unpleasant (affective characteristics) and 
includes as an essential part an awareness of some thought or 
object as the arouser of the emotion. However, this criticism 
is not applicable to James's own interpretation of his theory 
as we gave it above, for he insists only upon the organic dis- 
turbances as the essential element in emotion, not as the sole 
factor present. (2) If emotion is the consciousness of organic 
disturbances, how does it happen that the same emotion (fear) 
manifests itself differently in different individuals or in the same 
individual at different times? Some persons are paralyzed by 
fear, others scream, and still others run, or this variation in 
behavior may be true of one individual at different times. How 
can this be the same emotion with three such diverse types of 
organic disturbances manifested? The answer is clear and may 
take several forms: (a) Fear has not quite the same "feel" when 
one is paralyzed that it has when one can run or scream. To 
the extent that the bodily disturbances are different, to that 
extent the emotion is different (if the variation in bodily dis- 
turbances affects consciousness at all), (b) One must assume 
that if the different instances of fear have essentially the same 
feel or quality, it is because there is an inner core of organic 
disturbance which is common to all of the cases. (3) A different 
form of the same criticism is as follows: On the James-Lange 
theory how can one explain the fact that different emotions 
"express" themselves often in the same way? Some people 
cry in joy as well as in sorrow ; others grow pale in fear and also 
in anger. All emotions, when intense, tend to have the same 
organic disturbances and such cases could be endlessly multi- 
plied. The answer is, that where the emotional qualities 
really differ the variation must be due to a core of organic 
disturbance which varies with the different cases. In so far 
as the bodily disturbances are identical, to that extent the 
emotional experiences feel alike. There is no doubt that this 
is true in many intense emotions. Still the individual knows 



184 GENERAL PSYCHOLOGY 

whether he is deep in grief or in vengeful anger. This distinc- 
tion, however, is here one of the meaning rather than of the 
qualitative content. The individual knows that the cause of 
his condition is the loss of a dear one and not an assault upon 
his integrity, or vice versa. Apparently in many cases the 
distinction between one emotion and another is of this type, 
while the emotion is an emotion and not a mere cognitive state 
only by virtue of its organic resonance. (4) How can the James- 
Lange theory account for an emotion's appearing before the 
organic disturbances are present and disappearing before they 
wane? I am walking along calmly when suddenly a dog rushes 
toward me. I am badly frightened before there are noticeable 
organic disturbances. I now see that the dog cannot possibly 
reach me. At once my fear is gone, although the bodily com- 
motion may continue for some time. The explanation from 
the standpoint of the theory is twofold: (a) Certain fundamental 
internal organic changes may appear prior to external mani- 
festations, and condition in this way the early appearance of 
the fear. These same internal changes may cease upon my 
seeing that the dog is harmless, with the result that my fear 
also vanishes, (b) A second answer is to deny that the fear has 
actually vanished until most of the bodily disturbances are 
gone. It may be a different kind of fear, but still it is a real 
fear. What actually occurs in many cases is that the fear 
gives place to another emotion, that of relief, which in its turn 
is accompanied by certain specific organic changes, i.e., certain 
variations in muscular tension, breathing, etc. 

James held that the crucial test of his theory would come 
from an observation of patients totally anaesthetic. One of 
these cases he discusses at some length, that of Struempell's 
boy, who was totally anaesthetic save in one eye and one ear. 
Although nearly all incoming sensory impulses were thus cut 
off, the patient is said to have manifested grief and shame. 
James points out, however, that it is impossible to tell whether 



THE EMOTIONS 185 

he merely went through a few of the responses superficially con- 
nected with them or whether he actually experienced the 
emotion. Little can be hoped for from cases of this type, for 
unless the anaesthesia has been practically complete from birth, 
enough memory of previous experiences may be present to give 
the individual a faint but genuine experience of emotion. 

Sherrington's Experiment with Dogs. — The English physi- 
ologist Sherrington has sought to secure crucial evidence of 
the foregoing type on the James-Lange theory by experiments on 
dogs. The animals used had their spinal cords^ transected just 
below the medulla, thus having most of the sensory impulses 
from the body cut off as far forward as the shoulders. Pleasure, 
fear, anger, and disgust were still clearly shown in the head and 
fore-limb segments of the animals. Other experiments were 
made where the Xth cranial nerves (the vagi) were sectioned, 
whereby the stomach, lungs, and heart were removed from 
having any possible effects upon consciousness; and yet 
emotional expressions were manifested. Still other tests were 
made upon puppies nine weeks old, in order to verify a possible 
objection to the other tests that the emotional expressions 
secured were due to the effects of experience. In these cases, 
too, clear traces of emotions were present. As a result of his 
work, Sherrington holds that organic processes cannot be the 
essential elements of emotional experience. 

Two very significant objections are valid against these 
experiments, so far as they may be held to invalidate the 
James-Lange theory. (1) If the animals were conscious at all, 
no one knows how much of the "body" of their emotions 
vanished with the sectioning of the cord and nerves. The 
only fact that Sherrington has is that the movements in the 
anterior part of the animal were not changed in character or 
intensity by the operation. (2) There is no clear reason why 
the spinal animals should not have gone through certain instinc- 
tive reactions in their anterior segments. The nerves from the 



1 86 GENERAL PSYCHOLOGY 

eyes, ears, nose, mouth, diaphragm, and skin were still intact and 
sent impulses to the brain. The reflex arcs belonging to the 
fore-animal were still intact. The fact that the motor impulses 
could not reach the hind-animal and there result in muscular 
activity and in sensory impulses is no reason for inactivity 
in the fore-animal. It is doubtful if crucial evidence on the 
validity of the James-Lange theory can be secured by a method 
of this type. The introspective account is necessary before 
one can decide whether or not a given nerve injury changes the 
nature of the emotion. 

Cannon on Bodily Disturbances in Pain, Fear, and Rage. — 
Between 1909 and 191 5 W. B. Cannon, of the Harvard Physi- 
ological Laboratory, and his students published a series of 
papers chiefly concerned with the effects of pain, fear, and rage 1 
upon the activities of the digestive tract and with the presence 
of secreted adrenin and its effect upon the body during these 
emotional states. His results are of interest in our considera- 
tion of the James-Lange theory. Cannon has shown con- 
clusively that the normal contractions of the stomach and 
intestines are quickly inhibited by pain, fear, and rage. Not 
only is this condition true, but the salivary and gastric secretions 
are also checked. 2 This last point has been established by 
exposing a portion of the wall of the -stomach through a perma- 
nent fistula and noting the changes in gastric secretion here 
incident to the foregoing instinctive responses. The changes 
in salivary flow (the dryness of the mouth in fear, e.g.,) are 
matters of common knowledge. Inhibition of peristalsis in 
the intestines was demonstrated by observing the animal, prior 
to, and again during, the excitement, with the Rontgen rays. 
Prior to the excitement peristalsis would be progressing 

1 This should not be interpreted as a case of consciousness affecting 
the body. 

2 This was shown by a long series of observers, notably Pawlow, prior 
to Cannon. 



THE EMOTIONS 187 

normally, only to stop when the pain, fear, or rage appeared. 
These facts will undoubtedly account for a large part of the 
"feeling of heaviness," lassitude, etc., incident to grief and 
anxiety. 

The most interesting part of this work by Cannon, however, 
lies in the studies of the adrenal glands. These glands lie just 
anterior to the kidneys and are supplied by nerve fibers of the 
sympathetic system. They are ductless, pouring their secretion, 
adrenin, directly into the blood stream. Most of the data have 
been secured from cats by the use of careful surgical and physi- 
ological methods which space will not permit us to describe. 
Accordingly the following brief statements must represent for 
us the present status of our knowledge. The stimulation of an 
animal by pain or by the excitement in fear and rage is accom- 
panied by the stimulation of the adrenal glands through the 
fibers of the sympathetic nervous system. The adrenin con- 
sequently thrown into the blood results in: (a) driving the blood 
from the viscera to the skeletal muscles where it increases 
muscular efficiency; (b) increased conversion of glycogen from 
the liver into blood sugar; (c) decrease in muscular fatigue; 
and (d) decrease in the time required for the coagulation of the 
blood. These changes are all in the direction of increased body 
efficiency. The increased blood sugar puts more fuel at the 
disposal of the skeletal muscles, whence it is driven through 
the action of the adrenin. In the case of wounds, which usually 
result from pain, fear, and rage, the blood clots rapidly. No 
essential variation in these facts was found for the three excite- 
ments studied. Unfortunately we have no experiments avail- 
able for pleasurable, non-combative emotions, and consequently 
we are unable to say whether the above physiological changes 
do or do not occur in such cases. 

These studies open up in a vital manner the field of visceral 
disturbances, where James felt sure the fundamental "cores" of 
particular emotions arose. Cannon, however, wrongly interprets 



1 88 GENERAL PSYCHOLOGY 

his facts as antagonistic to the James-Lange theory. On the 
contrary they support the theory strongly by indicating 
a very delicate and widespread bodily disturbance during 
emotional seizures. Their only negative value is that here 
are two emotions, fear and rage, which cannot be differentiated 
on the basis of the organic disturbances produced by adrenin. 
Further delicate investigations might discover a differentiating 
factor even here. 

The Neural Basis of Emotion. — -If we accept the James- 
Lange theory that the essential component of emotional 
seizures is the complex of kinaesthetic, cutaneous, and organic 
sensations aroused reflexly by the stimulus, our account of the 
neural basis of emotion must be as follows: A certain stimulus, 
e.g., visual, sets up a sensory impulse in the optic nerve which 
passes through the thalamus to the occipital lobe. Here asso- 
ciated centers are excited with the result in consciousness that 
we "perceive a dangerous object." The nervous impulses now 
discharge back into the thalamus, mid-brain, and spinal cord 
and out over the motor nerves to the effectors. The activities 
of these muscles and glands stimulate sense-organs in the skin, 
muscles, and viscera, whereupon sensory impulses pass to the 
thalamus and thence to the post-Rolandic area. The awareness 
of bodily commotion now appears in consciousness. This 
fused with the perception or apprehension of danger forms the 
major part of the emotion. 

Recently Head and Holmes have contributed to our knowl- 
edge of the brain processes involved in emotion through their 
studies of patients with lesions in one half of the thalamus 
(unilateral thalamic lesions). When these lesions were in the 
anterior portion and consequently interrupted impulses from 
the thalamus to the cortex and vice versa, the following facts 
relative to emotions were noted on the side of the body affected: 
Irrespective of whether or not the body area to be studied was 
more or less sensitive than normal, pin prick, painful pressure, 



THE EMOTIONS 189 

extremes of heat and cold, visceral sensitivity, scraping, rough- 
ness, and vibration called forth on this area an excessive 
emotional response. The same was true for pleasurable stimuli, 
such as music. One patient, e.g., could not go to a concert 
because the affected part of her body became too excited! 
These results of Head and Holmes suggest very strongly that 
the essential brain center concerned in emotion is the thalamus, 
and that the influence of the cortex upon it is essentially one 
of control and inhibition. 

Present Status of the James-Lange Theory. — The preceding 
pages have given in some detail the evidence for and against 
the James-Lange definition of emotion. In so far as the oppos- 
ing evidence is theoretical, it can be convincingly answered; 
while the experimental facts so far available are not vital for 
the theory one way or the other. This evidence has its chief 
value in pointing out future lines of research, the source from 
which significant progress in the further understanding of 
emotion is most likely to come. In the present account emotion 
will stand as a state of consciousness whose essential character- 
istic is a core of certain organic, kinaesthetic, and cutaneous 
experiences instinctively aroused. 

Principles Underlying Emotional Disturbances. — In his 
classical discussion of the Expression of the Emotions (1872), 
Darwin presents three principles which are to explain the origin 
of the different motor accompaniments of emotion. The first 
in importance is the principle of serviceably associated habits. 
Many of the instinctive responses in man, for example, are 
clearly reminiscent of the days when his ancestors fought with 
tooth and nail. The increased muscular contraction in anger 
which results in the organism's assuming a large and threaten- 
ing aspect is obviously serviceable. We have seen how the 
secretion of adrenin aids the organism in mobilizing its energy 
quickly. And in a like manner we might enumerate the various 
reflexes and instincts which underlie the conscious experiences 



190 GENERAL PSYCHOLOGY 

called emotions, and in most cases (Darwin says "some") would 
be justified in assuming a "service" to the organism. The 
second of Darwin's principles is that of antithesis. The motor 
phenomena of this class are not, for Darwin, directly serviceable. 
He has in mind cases like the fawning of dogs and the affec- 
tionate behavior of cats. The principle is anthropomorphic 
and would be stated as follows: If a conscious state of one kind 
gave rise to a given motor disturbance, then the opposite con- 
scious state would give rise to the opposite motor disturbance. 
Affection, therefore, in the dog leads to the opposite type of 
behavior from anger. This principle is obviously at variance 
with the James-Lange theory. Undoubtedly if two emotional 
states are different in quality or feel (it is difficult to think of 
them as opposite) , they are so by virtue of the different instinc- 
tive reactions which underlie them, whose conscious accompani- 
ments they are. The different motor disturbances depend 
upon inherited connections within the nervous system and not 
upon the moments of consciousness. The third principle is 
that of direct nervous discharge. We are here to think of diffuse 
nervous activity. The nervous impulses overflow into neigh- 
boring centers, and in this way produce by accident certain 
forms of behavior which in themselves are apparently useless. 
These instances of behavior may possibly form an exception 
to the first principle and are illustrated by such cases as trem- 
bling, profuse perspiration, urination, and diarrhea in fear. 
Not only do these responses seem to have no real purpose; they 
may be positively disadvantageous to the organism in its 
adjustment to the environment. These three principles of 
Darwin's may be regarded as supplemental to the account of 
the origin of instinct presented in the foregoing chapter. 

Classification of Emotions. — Numerous classifications of the 
emotions have been proposed, each of which is based upon some 
one characteristic of emotional complexes and is at least valuable 
for calling our attention to that particular feature of the experi- 



THE EMOTIONS 191 

ence. Thus we have emotions grouped as pleasant or unpleas- 
ant; as sudden, gradual, or intermittent in mode of appearance; 
as depressing (asthenic) or invigorating (sthenic); as social or 
non-social; as immediate, retrospective, or prospective; and 
as simple or complex. Of these we shall discuss only the 
last two. 

Thomas Brown suggested the classification on the basis of 
temporal reference. In the immediate emotions there is no 
reference to time. Here belong such experiences as admiration, 
cheerfulness, melancholy, love, sympathy, pride, humility, 
wonder, and beauty. In the retrospective emotions reference 
is to some object as past, such as one finds in anger, regret, 
remorse, sorrow, and gratitude. Prospective emotions arise 
from situations referred to the future, such as occur in the 
emotions of hope, fear, worry, and desire. 

What is perhaps the most fundamental and thoroughgoing 
principle of classification is that of complexity. Certain emotions 
like fear and anger are primary and irreducible — they cannot 
be analyzed into component emotional parts. Others like 
admiration, envy, and sorrow can by introspection be analyzed 
into other simpler emotions. Conspicuous advocates of this 
system of classification are Bain, Ribot, and McDougall. The 
principle, moreover, may be interpreted genetically as well as 
analytically, for there is always the tendency to regard the 
simple, primary emotions as the first to appear in the life either 
of the race or of the individual. It is difficult, however, to 
determine the amount of truth in such an interpretation, though 
undoubtedly it can be relied upon to a large degree. 

Simple and Complex Emotions. — Fear, anger, and love 
(the tender emotion) are the emotions which Bain, Ribot, and 
McDougall agree are the simple ones, although, as we shall see, 
the latter two authors would include still others. By the tender 
emotions we are to understand something different from sex 
gratification and from the experience of love as that term is 



192 GENERAL PSYCHOLOGY 

usually applied. Love, we shall see, is a sentiment. The tender 
emotion is akin to sympathy and the parental feelings. It is a 
massive, pleasurable experience whose characteristic physical 
accompaniment is contact or the embrace. It is in this form 
that it occurs in very small children, and it is this form which is 
essentially maintained throughout life, although it may become 
abbreviated to a mere friendly slap on the back. McDougall 
finds its fundamental (instinctive) basis in the parental instinct. 
The stimuli which arouse it most readily are: helplessness or 
misfortune in a member of the same species; absence of bodily 
contact and warmth (particularly in children); and situations 
where gratitude is called forth. It is essentially a social 
emotion. 

Fear is intimately correlated with the instinct of flight. Its 
stimulus in adults is any threat too great to be resisted success- 
fully. Other things being equal, where this meaning (the over- 
whelming threat) attaches to an object the emotion appears in 
the individual against whom the threat is directed. Opposed 
to this general stimulus, which may be highly elaborated by 
experience, is that of the original stimuli to fear. Here we should 
probably class all intense stimuli — noises, lights, etc. — solitude, 
and strange surroundings. As a further stimulus Thorndike 
adds "being suddenly brushed or clutched" in the dark. It is 
perhaps the first emotion to appear in infancy, unless "satis- 
faction" at food and contact precedes. Ribot would trace in 
the individual a gradual development of fear, as well as of other 
emotions, from the crude instinctive fear to the specialized fears 
aroused as a result of personal experience with various objects. 

Anger is correlated with the instinct of pugnacity. Its 
stimulus in adults is any threat or obstruction which is not too 
great to be resisted. Fear and anger are fundamental for 
preservation. Anger probably appears later in infancy than 
fear and the tender emotion. According to Ribot it passes 
through three stages of development: first, the sheer animal 



THE EMOTIONS 193 

attack (with intent to destroy); second, a simulated aggres- 
sion in which no actual attack occurs; and third, a still more 
deferred type which appears in the form of envy, resentment, etc. 

To these three primary emotions of fear, anger, and the 
tender emotion Ribot would add pride, humility, and the sexual 
emotion (excitement). McDougall in his list would include 
disgust, wonder, sexual emotion, and positive (pride) and nega- 
tive (humility) self-feeling. 1 We may accept McDougall's list 
with the possible exception of disgust, into which an element 
of fear seems to enter and which is therefore complex. 

All emotions other than these primary ones are complex. 
They are resolvable into elements which are themselves faint 
arousals of the primary emotions. No account of an emotional 
experience is, of course, complete which stops with the listing 
of its component emotions, for the description must involve 
the points brought out in the foregoing systems of classification 
as well as an enumeration of the essential stimuli and organic 
responses. We want to know whether the emotion is sthenic 
or asthenic, prospective, retrospective, or immediate, etc., as 
well as whether it is simple or complex, and if it is complex 
what its components are. McDougall has made one of the best 
analyses of complex emotions into simple ones. The following 
quotation will indicate the type of method and results as well 
as the defects naturally involved in any description from a 
single angle of so complex a thing as a moment of consciousness : 

There is another group of complex emotions of which anger and 
fear are the most prominent constituents. When an object excites 
our disgust, and at the same time our anger, the emotion we experi- 
ence is scorn. The two impulses are apt to be very clearly expressed, 
the shrinking and aversion of disgust, and the impulse of anger to 
attack^ to strike, and to destroy its object. This emotion is most 
commonly evoked by the actions of other men, by mean cruelty or 

1 It is interesting to note that pride and humility are given a prominent 
place by British psychologists as early as Hume. 



194 GENERAL PSYCHOLOGY 

underhanded opposition to our efforts; it is therefore one from which 
original moral judgments often spring. It is, I think, very apt to 
be complicated by positive self-feeling — we feel ourselves magnified 
by the presence of the moral weakness or littleness of the other, 
just as on a lower plane the physical weakness or small ness of those 
about one excites this positive self-feeling, with its tendency to expand 
the chest, throw up the head, and strut in easy confidence. The 
name "scorn" is often applied to an affective state of which this 
emotion is an element; but, if this element is dominant, the emotion 
is that we experience when we are said to despise another, and its 
name is contempt, the substantive corresponding to the verb despise; 
scorn, then, is a binary compound of anger and disgust, or a tertiary 
compound if positive self-feeling is added to these; while contempt 
is a binary compound of disgust and positive self-feeling, differing 
from scorn in the absence of the element of anger. 1 

Aesthetic Emotions and Empathy. — The aesthetic emotion, 
or the enjoyment of the beautiful, is another complex emotion 
of particular interest, not only because of its social interest and 
value, but also because of a supposedly peculiar characteristic 
of empathy (Titchener's term) which it possesses. As an emotion 
aesthetic enjoyment is pleasurable, stable, of relatively low 
intensity; its component parts usually succeed each other 
slowly with a minimum of antagonism; and, finally, it is essen- 
tially relaxing and contemplative rather than exciting and pre- 
disposing toward practical activity. It is aroused by a great 
variety of stimuli which are consequently termed "beautiful 
objects." , The essential characteristics of these stimuli for 
the adult members of European culture we know in general. 
The stimuli, if auditory, must obey certain rules of melody, 
rhythm, harmony, and unity. If they are visual — as in painting 
and the plastic arts — they must obey certain rules of proportion, 
grouping, and design. The characteristics of the stimuli for 
the aesthetic emotion are not absolute, however, and the secret 

1 William McDougall. Introduction to Social Psychology (Boston: 
191 2), pp. 135-36, 



THE EMOTIONS 195 

of artistic genius is its ability to create its own rules and find 
out new and subtle ways of arousing the emotion. 

Lipps gave the name Einfiihlung {empathy) to the ascription 
of our feelings to the external object. A Doric column gives 
one the impression of balance and of lifting that which it 
supports. The "balance" and "lifting" are essentially mus- 
cular attitudes of the observer which are attributed to the 
column. In a similar manner one tends to imitate or mimic 
the attitudes, gestures, and expressions of the figures in sculp- 
ture and painting. By so doing he "enters into them." When 
one calls the day gloomy or sad, it is an instance of empathy, 
or, as Ruskin here terms it, of "the pathetic fallacy." 1 Stated 
in this manner, as the fusion of our emotional and subjective 
life with the external object, the principle and fact seem unusual. 
If we remember, however, that the "external object" is a visual 
or auditory perception, empathy no longer appears strange. 
"Unpleasant pain" and "exciting heart-beat" are also clearly 
instances of empathy, although here the "object" is a sensation 
located within the body. In art empathy is a case of fusion 
of the clear and analyzed (vision and hearing) with the obscure 
and unanalyzed, kinaesthetic-organic experiences. Outside 
the realm of art it is commonly known that two odors will fuse 
together, and that the muscular sensations from gagging will 
fuse with tastes and odors to constitute the experience of nausea. 
Artistic empathy is but a case of bodily disturbances (kin- 
aesthetic, organic, and cutaneous sensations) fusing with visual 
and auditory sensations. These latter two are the aesthetic 
senses (i.e., their stimuli include the "beautiful objects") largely 
because they can fuse in this manner with organic sensations 
and still preserve their individuality. Taste, smell, and 
touch on the other hand do not offer beautiful objects, and 
they do melt in with the consciousness of organic disturbances. 

1 In this form it is not far removed from the ontological argument of 
philosophy. 



196 GENERAL PSYCHOLOGY 

Accordingly, they do not retain their individual character. 
Viewed from this angle, we may consider empathy as one of 
the fundamental facts of emotional life. 

Mood and Temperament. — Moods and temperaments are 
not emotions. They represent more or less permanent pre- 
dispositions, or tendencies, to experience emotions of a certain 
type. An individual may be in a gloomy or a joyous mood, an 
angry or a fearful mood. These moods are of relatively brief 
duration, and they indicate that the person is particularly 
susceptible to depressing emotions or to pleasant ones, to com- 
bative or to fearful ones. By "predisposition" we mean that 
synaptic connections in the individual are so affected as to make 
probable the appearance of these types of emotions. The 
predisposition may be set up by indigestion, poor sleep, good 
or bad news, etc. A person whose mood is particularly incon- 
stant is "one of moods." The conscious states of the normal 
individual, however, are usually joyously toned. 

By temperament we refer to emotional predispositions that 
are probably innate and that probably vary but little during large 
periods of the individual's life. Historical usage has recognized 
four: the sanguine, the ardent (choleric), the nervous, and the 
phlegmatic. The sanguine are characterized as people of opti- 
mistic outlook, of ready but shallow emotional response. The 
ardent and the nervous are much alike, being individuals who are 
excitable, and whose emotions succeed each other rapidly and 
with more than medium intensity. They are the reformers and 
prophets. With the phlegmatic, on the other hand, emotions 
move slowly, are aroused with difficulty, and probably tend to 
be unpleasantly toned. The melancholic is also a temperament 
well recognized. Here depressive emotions tend to prevail, ap- 
pearing strong and massive in character, and moving slowly. 

Sentiment. — Sentiment is another term that we frequently 
hear in a layman's discussion of emotional experiences. Popu- 
larly it refers to any mild emotion and is often applied partial- 



THE EMOTIONS 197 

larly to a shallow form of the tender emotion. Shand, however, 
has given it a valuable technical significance. He has recog- 
nized that in addition to primary emotions and to their derived 
complex emotions there exist organized systems of emotions 
centered upon certain objects. This organized system of 
emotions is termed sentiment. The recognition of this fact 
takes us away from an atomic view of consciousness and 
behavior, and brings us face to face with the fundamental fact 
of continuity and integration. Anger, fear, joy, and sorrow 
are innately connected with each other in such a way that the 
"frustration of anger provokes a bitter sorrow, its satisfaction 
a peculiar joy of elation, obstruction to it, increase of anger, 
and the threatened loss of the sweets of revenge, when anger is 
deliberate and develops hate, may even excite fear." 1 A 
similar account could be written of fear, joy, and sorrow. 

Of the sentiments, love and hate are the chief in importance. 
To love a person (stimulus) is not to experience the tender 
emotion or the sex emotion constantly, or even to experience 
these alone. I may truly hate or love a person and yet not think 
of him during great intervals of time. An individual loved is 
above all an object vitally associated with all of the primary emo- 
tions, a stimulus at one time of fear, anger, sorrow. Chaucer has 
well described it in an oft-quoted passage from the "Romaunt of 
the Rose": 2 

Love it is an hatef ull pees, 

A free acquitaunce without relees, 

A truthe frette full of falsheede; 

A silkenesse all sette in drede, 

In hertis a dispeiryng hope, 

And full of hope it is wan hope, 

Wise woodnesse, and wode resoun, 

A swete perell in to drowne, 

Also a swete helle it is 

And a soroufull paradys, .... 

1 Alex. Shand. Foundations of Character (London: 1914), p. 37. 
a Ll. 4703 ff. 



198 GENERAL PSYCHOLOGY 

If the loved object prospers, I am joyous; if it is threatened, 
I fear or am angry; if it is injured, I sorrow and grieve. It is 
the center of a system of emotions. To speak of a system is 
to refer to an association between emotions or, better, between 
their physical correlates, instincts. This association is appar- 
ently inherited. We may therefore speak quite properly of an 
inherited co-ordination of instincts, the conscious side of 
which is the sentiment. A similar account could be given of 
hate, of parental affection, of ambition, etc. Emotions as they 
become vital factors in conduct and character enter into the 
type of systems or associations which we have described. 

The Function of Emotions. — A part of the function often 
assigned to emotions has been given to instinct in the preceding 
chapter. Emotions give warmth and value to the series of 
conscious states. Through empathy this personal phase is 
transferred to impersonal objects, and "Nature" takes on an 
"interesting" light. Without emotions the stream of con- 
sciousness would be "coldly" intellectual. This condition is 
occasionally remotely approached by apathetic or severely 
intellectual persons. 

To say that emotions aid in memory, affect attention, and 
help in the adjustment of the organism to its environment is 
practically true. The memory of emotionally vivid experiences 
is exceptionally good, for attention in such instances is highly 
concentrated and absorbed by the excitement, a situation that 
facilitates good retention. Emotion does occur during critical 
moments of adjustment, but to assert that it actively functions 
in any of these adjustments is to assign a causal connection of 
mind and matter which cannot be justified. Emotion occurs 
parallel with, or subsequent to, the nervous activities which 
condition empathy, memory, attention, and adjustment in 
general. Such a statement, however, takes from emotional 
experience neither one jot nor one tittle of its intense human 
value. 



THE EMOTIONS 199 

REFERENCES 

Angell, James R. "A Reconsideration of James's Theory of Emo- 
tion in the Light of Recent Criticisms," Psych. Rev., XXIII 
(1916), 251 ff. 

Bain, Alex. Emotions and Will. Third edition. London: 1875. 

Brown, Thomas. Lectures on the Philosophy of the Human Mind. 
Two vols. Boston: 1838. 

Cannon, W. B. Bodily Changes in Pain, Fear, Rage, and Hunger. 
New York: 1915. 

Darwin, Chas. The Expression of Emotions in Man and Animals. 
New York: 1873. 

Head, Henry, and Holmes, Gordon. " Sensory Disturbances from 
Cerebral Lesions," Brain, XXXIV (1911), 109 ff. 

James, Wm. "What Is an Emotion?" Mind, IX (1884), 189 ff. 

. Principles of Psychology, Vol. II, chap. xxv. New York: 

1890. 

. "The Physical Basis of Emotion," Psych. Rev., 11(1894), 



516 ff. 
Lange, K. Uber Gemiithsbcwegungen. Leipzig: 1887. 
Lee, Vernon, and Thompson, C. A. Beauty and Ugliness. New 

York: 191 2. 
McDougall, William. An Introduction to Social Psychology. Third 

edition. Boston: 191 2. 
Ribot, Th. The Psychology of the Emotions. Second edition. Lon- 
don: 1911. 
Shand, Alex. Foundations of Character. London: 19 14. 
Sherrington, C. S. "Experiments on the Value of Vascular and 

Visceral Factors for the Genesis of Emotion," Proc. Royal Soc. 

London, LXVI (1900), 390 ff. 
Titchener, E. B. "An Historical Note on the James-Lange Theory," 

Amer. Jour. Psych., XXV (1914), 427 ff. 



CHAPTER V 
THE AFFECTIVE PROCESSES 

Introduction. — -From a study of the emotions we pass 
naturally to an analysis of affection, or the affective processes. 
Reference has already been made to the characteristics of 
pleasantness and unpleasantness which attach to many emotions. 
These are the two affective processes upon whose existence 
psychologists agree. There is no chapter in modern psychology 
in which less is definitely known than here — and yet pleasantness 
and unpleasantness are conscious states of admittedly great 
importance. It is extremely difficult to observe them minutely, 
and in this respect their study may take rank along with the 
most difficult problems of observation and description in biology. 
Even when we approach them from the standpoint of their 
correlated bodily changes the study is quite as baffling and 
the facts just as elusive as from the side of the conscious 
processes. 

On the side of the behavior of the organism, pleasure is inti- 
mately connected with reactions of approach to, and unpleasant- 
ness with reactions of retreat from, the stimulus. The conscious 
state of pleasantness, furthermore, seems to be aroused especially 
during moments favorable to the organism, and unpleasantness 
during unfavorable moments. It is largely for this reason that 
some writers have claimed that even animals as low in the scale 
as the amoeba and paramecium have a vague consciousness 
of pleasantness and unpleasantness correlated with their posi- 
tive and negative responses. We have already seen, however, 
that the ascription of consciousness to such simple organisms is 
extremely precarious. When we know exactly what bodily 
conditions underlie these conscious states in man, we shall be 

200 



THE AFFECTIVE PROCESSES 201 

in a better position to decide concerning the validity of such an 
inference. 

The affective processes differ from emotions pre-eminently 
in their lesser intensity. Pleasantness and unpleasantness 
never reach the degree of excitement attained in fear, anger, 
and jealousy. Most psychologists believe that the affective 
processes are also less complex than the emotions. It is not 
clear, however, that they are less complex than mild fear, anger, 
or joy. From the standpoint of how the experiences feel, 
pleasantness is not unlike mild joy, and unpleasantness is not 
markedly unlike a subtle anger. Furthermore the two affect- 
ive experiences, as they increase in intensity, pass over readily 
into the two emotional experiences. In addition to this simi- 
larity to emotions, psychologists are agreed that there is a very 
great similarity between the feel of affective processes and the 
feel of organic and cutaneous experiences such as tickle, lust, 
and pain. By most psychologists, however, pleasantness and 
unpleasantness are regarded (perhaps incorrectly) as irreducible 
conscious states different from sensation. All conscious states 
would then be resolvable into these two mental elements — ■ 
sensations and affections. For the present we shall confine our 
attention to a description of the affective processes, leaving the 
nature of sensation for discussion in the following two chapters. 

Attributes of Affective Processes. — We can best secure an 
introduction to the nature of the affective processes through a 
consideration of their essential attributes. Each affective state 
possesses in some degree the attributes of intensity, duration, 
quality, clearness, location, and meaning. There is agreement 
among psychologists upon the first three of these attributes. 
The only dispute is over the number of qualities. Ordinarily 
it is said that there are two irreducible qualities, pleasantness 
and unpleasantness. Wundt, however, declares for six qual- 
ities: strain, relaxation, excitement, calm, pleasantness, and 
unpleasantness. There is no doubt that such conscious states 



202 GENERAL PSYCHOLOGY 

exist and do play a prominent role in daily life. The question 
is whether they are all irreducible, unanalyzable, elemental. 
It is pretty generally agreed that strain and relaxation are com- 
binations of kinaesthetic and organic experiences coming from 
the muscles and viscera. The same statement is applicable 
to the awareness of excitement and calm, although these 
are more difficult to analyze. Pleasantness and unpleasant- 
ness are the most difficult of all to analyze, yet many psychol- 
ogists regard these, too, as combinations of sensory processes. 
Wundt's hypothesis of three pairs of affective qualities has the 
great merit of recognizing the complexity of aff ective experi- 
ences, for it seems more plausible that our feelings, other than 
those that are obviously emotions, are composed of combinations 
of six qualities rather than of only two. His position is an 
increasingly important one when attention is called to the 
antagonistic character of the members of each of the three pairs. 
The affective qualities of pleasantness and unpleasantness are 
mutually exclusive. They cannot coexist in consciousness. 
This is also true of strain and relaxation and of excitement and 
calm. Moreover, Wundt's point of view recognizes affective 
experiences that are at the same time relaxing, calm, and 
pleasant, or that consist of any other combination of three 
qualities where no two are opposites. Each affective quality 
may decrease to zero, then giving place to its opposite, as a 
pleasantness may grow less and finally give place to an increasing 
unpleasantness. In the last few sentences we have been com- 
menting upon an attribute supposed to be peculiar to affection, 
viz., the antagonistic character of the elements in the pairs of 
affective qualities. We shall come back to this problem in the 
following section. 

Let us return to the list of attributes given above. When 
psychologists insist that the affective processes lack clearness, 
they mean that these processes lack focal clearness. In other 
words, they cannot be attended to directly. If a person is eating 



THE AFFECTIVE PROCESSES 203 

sweet candy and if the experience is pleasant, he nevertheless 
cannot put his mental finger, so to speak, upon the affective 
process. If he attempts to bring the pleasantness into the 
focus of attention he will find that he brings in the sensation of 
sweetness, of contact, or of temperature, but that always the 
pleasantness itself evades him so that he never can say, "Here, 
I have it!" Many psychologists insist, however, that an affect- 
ive process can be brought into the focus of attention. In 
whatever way skilled observers may finally settle the question, 
it is certain that even though affective processes may not enter 
the area of maximal clearness, they must, so far as they are 
conscious states, be clear in some degree. 

Location is another disputed attribute. Can an experience 
of pleasantness be located at some part of the body, or is it an 
experience that pervades the entire organism? Can the 
pleasantness of the taste of candy be localized in the mouth, or 
is it only the taste and contact that are there? Here again 
answers differ. The question, however, formulated in this 
manner, is not so much a question of whether the affective 
process is localized as it is a question of how definitely it can be 
localized. One cannot definitely localize a pure tone or a faint 
odor. What one does is to locate them, now here, now there, 
but always in external space. Similarly the affective processes 
are at least localized within the body — save in the cases of 
empathy discussed in the preceding chapter. When the localiza- 
tion is within the body, individuals obviously differ greatly 
in the definiteness and accuracy with which the localization can 
be accomplished. To one it may seem that the pleasantness 
of music is located in the facial muscles and in the chest. To 
another such a statement seems absurd, for to him the pleasure 
may pervade his entire body. However, in either case localiza- 
tion of a kind is present. 

Meaning is an attribute ordinarily assigned to sensations 
and images. Inasmuch, however, as the neural processes which 



204 GENERAL PSYCHOLOGY 

underlie affective processes must be related to other neural 
processes, meaning on the conscious side must be attached to 
affective qualities. Observation verifies this. At one moment 
pleasantness may mean food; at another, rest; and again, 
the approach of sleep. We may unhesitatingly say that when- 
ever an affective quality appears in consciousness as a concrete 
actual experience, it has some significance. This significance 
is its meaning. 

Aside from the general attributes which have just been 
discussed, the individual charactersitics that are peculiar to 
affective processes, or that are often said to be peculiar, may best 
be considered by comparing affection and sensation. 

Affection and Sensation. — -By sensation we are to under- 
stand such things as the consciousness or awareness of red, green, 
and purple in vision, and of noise and tone in audition. Sensa- 
tion involves the activity of a specific segment of the nervous 
system extending from the sense-organ to the cortical center. 
Affection, on the other hand, is said to depend not on the 
activity of a specific segment of the nervous system but upon 
the mode of functioning of the nervous system as a whole. The 
evidence upon which such a statement rests is as follows: 
(i) The affective qualities may accompany any sensory activity, 
visual, auditory, cutaneous, etc. Furthermore there are no 
sense-organs peculiar to pleasantness and unpleasantness as 
the eye is peculiar to vision and the ear to hearing. (2) Affect- 
ive qualities are diffused throughout the organism and cannot 
be localized definitely within it, a condition which would indicate 
a dependence upon widely spread nervous activity. With 
regard to the second point just given, we have already called 
attention to the fact that the ability to localize accurately within 
the body is maintained by various observers. It should also 
be noted, moreover, that many sensations and combinations of 
sensations diffuse throughout the body. A feeling of warmth 
or chilliness spreads over the entire organism; colicky pains are 



THE AFFECTIVE PROCESSES 205 

voluminous; and the general sensory complexes termed "feel- 
ings of malaise" and "feelings of vigor and bodily well-being" 
are diffused throughout the entire body. The localization which 
they possess is merely a reference to the body as opposed to the 
external world. It is therefore clear that this second bit of 
evidence fails to separate affection and sensation. With respect 
to the first bit — that pleasantness and unpleasantness are not 
correlated with a specific sense-organ— it may well be pointed 
out that neither is emotion so correlated. Fear, anger, scorn, 
etc., may be aroused by objects affecting the ear, eye, tongue, 
nose, or any other sense-organ. Yet we saw in the last chapter 
that the essential element in emotion is the consciousness of 
organic, kinaesthetic, and cutaneous sensations. So far as the 
evidence goes, affective processes may well be essentially the 
consciousness of a fusion of the same kind of sensory processes. 
Wundt's addition of strain-relaxation and excitement-calm to 
the affective dimensions is supporting evidence, for, while Wundt 
does not so interpret it, other psychologists insist that the 
qualities that he adds are combinations of sensations. Yet the 
only difference between the three pairs is one of ease of analysis 
into elements. If affective processes are not essentially sensa- 
tion fusions, their neural basis must be an activity originating 
in the cortex (centrally aroused brain activity) as opposed to 
an activity originating in a receptor (peripherally aroused brain 
activity) . 

A little later in this chapter we shall consider the bodily 
disturbances accompanying the affective processes. To the 
extent that definite bodily processes can be found, to that extent 
are we able to construct the probable neural basis. These 
bodily disturbances come to consciousness as fusions of sensa- 
tions. Titchener has advanced the speculation that relatively 
simple undeveloped receptors in the viscera may be the origin 
of the neural activity underlying affection. Such a view implies 
the sensory quality of affection because it specifies that the 



206 GENERAL PSYCHOLOGY 

neural acitivity originates in the periphery, i.e., in the receptors. 
(Titchener, however, regards affection and sensation as two 
distinct mental elements.) 

Psychologists have also suggested that sensation and affec- 
tion differ in that the former is objective and the latter sub- 
jective. 1 But emotions are subjective and so are the sensation 
complexes of "malaise" and "well-being" above mentioned. 
Whether a given state of consciousness is called objective oe 
subjective depends upon its localization inside or outside the 
body and upon its extent or diffusion. This attempted differ- 
entiation of sensation and affection sometimes proceeds along 
another line. Sensations are said by Angell to give us the what 
of experience while affections give us the how. A sensation 
tells us that the object is red, or middle C (in music), or hot. 
The affective process on the other hand tells us how these 
qualities affect us, pleasantly or unpleasantly, etc. But the 
how may become the what, paradoxical as it may sound. If 
what I wish to know is how a given quality affects me, if what 
I want to know is the affective content of consciousness, then 
the above paradox is accomplished. Perhaps usually the affect- 
ive processes are the dominantly subjective side of conscious- 
ness, and perhaps they are usually the how of our attitude toward 
objects. They are not, therefore, conscious states which differ 
from sensations as one element from another. Fear and anger 
are also "how" aspects of experience; yet they are essentially 
sensory fusions. Kinaesthetic, organic, and cutaneous sensa- 
tions go to make up the consciousness of our body as present, 
and in this manner they naturally form the background upon 
which external, objective states of consciousness are projected. 
This is a further reason why the affective processes are so inti- 

1 The term subjective is not used here to refer to the illusory and 
hallucinatory aspects of experience. One may fancy he hears his name 
called and still localize the call outside his body, and in this sense regard it 
as objective. 



THE AFFECTIVE PROCESSES 207 

mately connected with the feeling of self or personality. 
Accordingly, to know what affects a person pleasantly, un- 
pleasantly, excitingly, or calmly, with strain, or relaxation, 
is to know the innermost secrets of his nature. 

In the preceding section we took up the question of the 
antagonism of the members of each pair of affective qualities. 
Pleasantness is antagonistic to unpleasantness because it cannot 
coexist with it, that is, a person is either pleased or displeased. 
These two conscious qualities may alternate with great rapidity, 
but they cannot be in consciousness at the same time. The 
same thing is true of strain-relaxation and of excitement-calm. 
This attribute of mutual exclusiveness is held by certain psy- 
chologists to be peculiar to affective processes. But many sensa- 
tions cannot coexist. They either cancel each other or fuse into 
a new experience that cannot well be analyzed. Two tones of 
the same pitch sounded on the same type of instrument do not 
continue to exist as separate tones but fuse into a single tonal 
experience. Two odors will not coexist in consciousness. 
Either they will alternate rapidly (rivalry), or they will fuse 
to make a new and unanalyzed odor, or they will cancel (com- 
pensate) each other, leaving no odor at all. Organic sensations 
are further notable cases of fusion, of inability to exist simul- 
taneously in consciousness. This attribute is, therefore, clearly 
not peculiar to affective processes. 

The net result of our inquiry here, therefore, is that affect- 
ive processes are quite probably not separate mental ele- 
ments, but are fusions of organic, kinaesthetic, and cutaneous 
sensory processes. Because the problem of adjusting our- 
selves to our environment is the dominant one, the focus of 
consciousness, i.e., the place of the clearly analyzed experi- 
ences, is most often rilled with visual and auditory data. Only 
in the neurotic and neurasthenic do the kinaesthetic, organic, 
and cutaneous sensations dominate the focus during consider- 
able intervals of time. We may therefore think of consciousness 



208 GENERAL PSYCHOLOGY 

as dominated usually by "intellectual" rather than by "feeling" 
experiences. 

Stimuli for Affective Processes. — Under the heading of 
stimuli we must consider those internal and external conditions 
whose presence is normally followed by one or another of the 
affective qualities. Most of our information bears upon the 
qualities of pleasantness and unpleasantness. 

Unpleasantness is usually excited by the sensation of pain, 
by sensations and ideas of great intensity or of great duration. 
Stimuli which occur suddenly and accordingly command 
involuntary attention are perhaps usually unpleasant. (Of 
course, where objects are referred to as pleasant, unpleasant, 
exciting, etc., we are dealing with cases of empathy, of fusions 
of the internal with the external processes. We do not mean 
that pleasantness is a characteristic of the object as its color is.) 
Historically great emphasis has been laid upon the fact that 
whatever thwarts our purpose or the ongoing activity of the 
moment is unpleasant. This explanation received its first 
important treatment from Herbart. If one is engaged in the 
study of a mathematical problem, whatever appears in con- 
sciousness unrelated to the solution is unpleasant. Likewise, 
if one is walking and a break in the path interferes with the 
ongoing automatism, unpleasantness usually appears in con- 
sciousness. It is interesting to note, in connection with our 
discussion of emotion in the preceding chapter, that the thwart- 
ing of purposes is one of the customary stimuli for anger. 
Whether the feeling reaction shall appear as anger or as un- 
pleasantness depends upon the intensity and significance of the 
interference. Closely related to the conditions of unpleasant- 
ness which have just been mentioned is this fact: any using 
up of more energy than the sense-organ or muscle ordinarily 
has access to is usually unpleasant. Thus a too prolonged 
stimulation or a too intense stimulation, a too prolonged or a 
too intense muscular exertion, is unpleasant. 



THE AFFECTIVE PROCESSES 209 

To a certain extent pleasure is excited by the opposite type 
of stimulus from that which arouses unpleasantness. Stimuli 
which arouse activities within the normal capacities of the 
receptors and effectors are ordinarily pleasant. The objects, 
however, must not be of too brief duration or of too slight 
intensity, for, if they are, the difficulty of attending to them 
results in unpleasantness. Those objects (sensations) which 
usually favor or aid our purposes and ongoing activities are 
pleasant. Accordingly ease as opposed to difficulty of attention 
is pleasant. Again, it is interesting to note that the objects 
and relations which produce pleasure also produce joy when 
their intensity or significance is greater. 

Stimuli from Art. — So far no mention has been made of 
the great class of beautiful and ugly objects, aesthetic and 
unaesthetic stimuli, that arouse pleasantness and unpleasant- 
ness. Since to outline carefully the characteristics of these 
objects is to write a treatise on aesthetics, at the present point 
we can merely mention a few salient points. Melodies, rhythms, 
and musical harmonies are examples of aesthetic stimuli for 
pleasantness. Accidental causes such as constant and inoppor- 
tune repetition may make them unpleasant, but intrinsically 
they are pleasant. Much experimentation has been made upon 
the affective values of colors and designs. The method used 
is termed the method of impression. In one of its common 
forms it consists in comparing each of many colors, color com- 
binations, or designs with every other color, color combination, 
or design in the series of objects chosen for study. Each time 
that the observer is confronted by two of the objects he indi- 
cates which is the more pleasant. The final results can be put 
in the form of averages and curves which will indicate quantita- 
tively the relative merits of the different objects as stimuli 
for pleasantness and unpleasantness. A similar procedure 
is applicable to strain-relaxation and to excitement-calm. 
Material is selected and graded according to its capacity to 



210 GENERAL PSYCHOLOGY 

arouse these qualities in the observer's consciousness. By 
these methods it is possible to determine the effect upon the 
affective process of changes in the intensity, duration, and 
quality of the sensation (object). Although the results differ 
markedly from one individual to another, for the same individual 
the data are perhaps surprisingly constant. If deep (saturated) 
colors are preferred or if oblongs are preferred to squares, it 
does not follow, of course, that this is due to the innate organiza- 
tion of the individual. The yellow may be associated with some 
happy experience or the square with something distasteful. In 
agreement with this we know that the objects which are con- 
sidered pleasurable and aesthetic have changed greatly in 
historic times and do change greatly during the life of the indi- 
vidual. Racial tradition also seems to fix an association between 
certain visual qualities and certain affective states. Reds and 
yellows are symbols of passion and excitement. Red is the 
color of blood, of danger signals, and of revolutionary flags. 
Yellow with many peoples is a sacred color signifying aspiration. 
Greens and blues are cool, calm, and quieting colors. White 
is the occidental symbol of innocence and purity; black, the 
symbol of melancholy and depression. The theories for the 
causal bases of these associations offer most interesting problems, 
but problems into which we cannot enter. 

Bodily Changes in Affection. — Not only must we know the 
stimuli that bring about affective consciousness, but we must 
know the organic results within the individual. Studies of 
the bodily changes which accompany affective states have con- 
cerned themselves with changes in circulation, breathing, 
muscular tonicity, and electrical potential. Here we use the 
method of expression as opposed to that of impression discussed 
above. One should not, however, regard the bodily changes as 
"expressions" of affective processes. They are the accompani- 
ments and possibly the objective side of affection, a case similar 
to that which we found in the problem of the emotions and their 



THE AFFECTIVE PROCESSES 



211 



accompanying organic disturbances. In the study of circu- 
latory and respiratory changes the same apparatus is used which 
we have described in the account of attention (p. 130). In 
general the only result one can be sure of is that all affective 
processes are accompanied by changes in the body systems 
referred to. There is no clear evidence that the disturbances 
differ according to the affective quality present. Wundt and 
his students are the chief champions of the opposite view. 
Table I gives the correlations which they claim to find between 

TABLE I 

Relations between the Feeling Qualities and Changes 
ln Pulse and Breathing according to Wundt 

(+ indicates an increase; — indicates decrease; = indi- 
cates no change) 





Pulse 


Breathing 


Feeling 


Strength 


Speed 


Strength 


Speed 


Tension 


+ 
+ 
+ 


+ 
+ 


+ 

+ 
+ 




Calm 


_ 


Unpleasantness . . 

Pleasantness 

Excitation 

Relief 


+ 
+ 







affection and organic disturbance. The work has been repeated, 
particularly by James R. Angell and by Shepard in this country, 
with results that differ from those secured by the German school. 
The two great sources of error that apparently render correla- 
tions of this type permanently impossible are these: (1) The 
affective states are difficult to control. Although the stimulus 
given, e.g., an unpleasant odor, may be unpleasant, the act of 
attending and the success of the test may themselves introduce 
pleasant affective qualities, or vice versa. (2) The sensory 
stimulation itself sets up circulatory and respiratory changes 



212 GENERAL PSYCHOLOGY 

which obscure any effect that may accompany the affection 
proper. The large and dominating fact that stands out from 
these studies is the close connection which exists between con- 
scious states (cerebral neural processes) and bodily changes. 
So far, however, the study of these bodily changes has thrown 
little or no positive light upon the nature of the affective 
processes. 

Affective Memory. — To what extent and in what manner 
do we remember experiences of pleasantness and unpleasant- 
ness? The question can well be broadened to the general one 
of emotional memory. To have an affective memory is to be 
able to reinstate or recall an affective process which has once 
been experienced. Many fail here, although most people can 
succeed in remembering that such and such an experience had 
such and such an affective tone. The latter case needs no com- 
ment other than will be made in the chapter on "Memory." 
The former possibility, on the other hand, deserves special 
attention. 

One major difficulty in securing true affective memory lies 
in the fact that a remembered unpleasantness may be swallowed 
up in the pleasure of its successful recall. When one looks then 
for the old unpleasantness in the experience that is recalled, he 
does not find it, although he may recall distinctly what affect- 
ive tone was originally present. This fact has usually been 
described by saying that an experience which in the beginning 
had one affective tone finally may emerge in memory with 
another. It seems probable, indeed, that the change in affect- 
ive quality when the experience is recalled is due to the con- 
ditions under which the recall takes place. When I remember 
a boyhood experience that was pleasant, it may serve now 
to divert my thoughts from their proper channel and hence 
be unpleasant; or it may call up another experience whose 
unpleasantness overshadows the faint re-arousal that I had 
secured of the original pleasure. 



THE AFFECTIVE PROCESSES 213 

Confusion has been introduced into the question through 
the insistence by some psychologists that if affective memory 
occurs, the original pleasantness must not here and now diffuse 
through the body and so be actually present, but must reappear 
as a faint copy of the original just as an image is a faint copy 
of its sensation. If the affective quality in the beginning is due 
to sensory impulses, when it is revived it must be due, it is said, 
to processes which originate in the cerebral cortex or in the 
thalamus. There is a fundamental misconception here, how- 
ever, because any state of consciousness which we recognize as 
one of our past experiences is a state of memory consciousness. 
Undoubtedly in most cases of emotional memory one actually 
experiences faint present anger, fear, jealousy, unpleasantness, 
etc.; nevertheless they are memory experiences. The present 
solution of the question will take on added significance in the 
study of association and memory which we shall make later in 
the book. 

Functions of Affection. — Throughout our study of affections, 
we have found correlations with our account of emotions. The 
question of function offers no exception to the rule, for in both 
processes it is essentially the same. Here with affection most 
of our probable knowledge is with reference to the qualities of 
pleasantness and unpleasantness. The most important func- 
tion that has been credited to them is in connection with the 
fixing of associations between ideas and muscular responses 
(habit-formation). In connection with the topic of psycho- 
analysis, it was seen that the unpleasant tends to be repressed 
and the pleasant recalled. Furthermore, the description of 
habit-formation in animals gave data which would suggest 
that the animal eliminated those responses that led to unpleas- 
antness and retained those that led to pleasantness. This 
is often referred to as "the stamping-in effect" of pleasure. 
This function of affection is quite probably a genuine one; only 
here, as in emotion, it should be held clearly in mind that not 



214 GENERAL PSYCHOLOGY 

the conscious states but the nervous processes underlying them 
are the agencies which "stamp in" or favor certain responses. 
Synaptic resistances are seemingly decreased by virtue of their 
association with nervous impulses underlying pleasure. 

In addition to these functions, affection also confers "value" 
upon other conscious states (empathy) and aids in determining 
the content of the focus of attention by holding attention to the 
pleasant. Perhaps all of the functions of affection are of great 
ethical import. Since the Greeks it has been recognized that 
voluntary action or conduct is tremendously influenced by the 
pleasure or the lack of pleasure which the future holds in store. 
Certain it is that individual and national conduct is always 
directed toward securing happiness, one of whose essential 
elements is a mild and not too turbulent pleasure. 

REFERENCES 

Angell, J. R. Psychology, chaps, xiii and xiv. Fourth edition. New 
York: 1908. 

and McLennan, S. F. "The Organic Effects of Agreeable 

and Disagreeable Stimuli," Psych. Rev., Ill (1896), 371-77. 

Ellis, Havelock. "The Color Sense in Literature," Contemp. Rev. 
(1896), 714-29. 

Fernberger, S. W. "Note on the Affective Value of Colors," Amer. 
Jour. Psych., XXV (19 14), 448-49. 

Gordon, Kate. Esthetics. New York: 1909. 

Herri ck, C. J. Introduction to Neurology, chap, xviii. Philadel- 
phia: 191 5. 

Ladd, G. T., and Woodworth, R. S. Elements of Physiological Psy- 
chology, Part II, chap. vii. New York: 191 1. 

Titchener, E. B. Elementary Psychology of Feeling and Attention. 
New York: 1908. 

. Text-book of Psychology, pp. 225-65. New York: 1910. 

Wundt, Wm. Outlines of Psychology, pp. 83-99. Trans, by Judd. 
New York: 1907. 



CHAPTER VI 

SENSORY PROCESSES 

Introduction. — With the analysis of the affective processes 
the first part of our study is completed. At the close of the 
discussion of the nervous system two series of topics were before 
us: either we could start with the effector side of the reflex 
arc and study forms of muscular and glandular behavior and 
their conscious accompaniments (emotion and affection), or we 
could follow the series of topics growing out of an analysis of 
receptor activities (sensation, imagination, memory, etc.). 
We chose the former of these topics because it includes the 
primitive and fundamental sides of human nature — instinct 
and emotion — for in the chapter on "Attention" notice had 
already been taken of the overshadowing role of instinct in 
determining the contents of the focus of consciousness and 
consequently the constituents of character. In this way 
instincts, inherited co-ordinations of reflexes, are determiners 
of what sensations, images, and thoughts we shall be conscious. 

In the series of topics whose study we now begin there will 
still be the two phases behavior and consciousness, and our 
account cannot be adequate without due note being taken of 
each. Indeed, as our previous study has indicated, much of 
our knowledge of neural processes and behavior is based upon 
the circumstantial evidence offered by the nature of conscious 
processes. 

Definition of Sensory Processes. — By sensory processes, 
or sensation, we shall understand the consciousness of any object 
as present to sense. If I am aware of a color or a sound, a contact 
or an odor, and if I believe that it is due to the actual presence 
of an object to my senses, I am experiencing a sensation. My 

215 



216 GENERAL PSYCHOLOGY 

belief may be poorly founded, and there may really be no sound 
or odor present. In this case we refer to the experience as an 
illusion or a hallucination; yet for me it remains a sensation 
by virtue of the belief in the physical presence of its cause. 
Except in rare instances the cause of the sensation is actually 
present and acting upon the sense-organs; and so the belief 
is well grounded. It is this attitude of belief that consti- 
tutes the "feeling of realness" attaching to sensation and 
lacking in imagination, which early psychologists referred 
to as the "force and liveliness" of sensation. This belief 
characteristic of sensation is one of meaning or significance, 
for the conscious experiences involved mean "an object present 
to sense." 

In addition to the fundamental characteristic of force and 
liveliness just mentioned, sensation possesses the following 
attributes which it shares with all other states of consciousness: 
quality, clearness, intensity, duration, meaning, and location. 
Each of these attributes will vary in degree. The location may 
be more or less definite; the meaning may change both in com- 
plexity and in significance. The quality is the attribute which 
language has recognized with a specific name : color names refer 
to qualities of vision; sweet, salt, sour, and bitter are the ele- 
mental qualities of taste — and we could give examples from 
every sense field. In the preceding chapter we had occasion 
to discuss the attribute of clearness as it concerned affective 
processes and sensations. All psychologists agree that sensa- 
tions may enter the focus of consciousness, i.e., that they can 
be directly attended to. Very faint and poorly localized sen- 
sations (odor, for example), however, probably enter the focus 
with as little ease as do affective processes. We have inclined 
decidedly toward the view that affection is peripherally arousecf, 
and hence that it like emotion is essentially sensory in char- 
acter. Certain attributes or characteristics of sensations are 
normally peripherally initiated, i.e., the nervous activities 



SENSORY PROCESSES 217 

underlying them must start from a sense-organ at the periphery 
of a reflex arc and then proceed to the cortical area involved. 
These peripherally conditioned characteristics are quality, 
intensity, and duration. The other attributes mentioned 
depend more largely upon processes arising within the 
brain. 1 

Sensation, Perception, and Apperception. — Many psy- 
chologists distinguish between sensation and perception on 
the basis of meaning. James, for example, refers to sensations 
as "awareness of quality" and to perception as "knowledge 
about" objects. Perception thus involves a relationship to 
past experiences (meaning), whereas sensation stands by itself 
simply as blueness or grayness or sweetness. In this form, 
however, James himself admits that sensations do not exist 
after the first hypothetical moment of consciousness. Only 
the very first experience of an infant could enter into no rela- 
tionships with past experience and therefore could have no 
meaning, could only be an "awareness" and not a "knowledge 
about." It is idle, however, to spend time seriously with such 
sensations, and we use the term here for the simplest actual 
bit of sensory consciousness, thus making it synonymous with 
James's perception. The term perception is better used, if 
used at all, to refer to any object present to sense which is com- 
posed of two or more sensory qualities. If one sees a bit of blue 
(quality), of a certain intensity, clearness, duration, location, 
and meaning, 2 he experiences the state of consciousness termed 
sensation. On the other hand if what one sees is two or more 
qualities — red, white, and blue, e.g. — plus the other character- 
istics mentioned, he experiences a perception. The meaning 
this time may still be sky, or it may be flag, the only difference 

1 This is true to some extent of intensity and duration also. Hard-and- 
fast rules cannot be laid down. Sensory quality, however, is usually and 
predominantly peripheral in origin. 

2 The bit of blue might mean anything: paper, blotter, sky, etc. 



218 GENERAL PSYCHOLOGY 

between the two cases being one of qualitative complexity. In 
each case there is the awareness of an object. 1 

Apperception, to use Herbart's description (1816), has been 
denned as the reception of a new stimulation into consciousness 
by past experience. Past experience constituted the appercep- 
tion mass and the novel idea or sensation was the apperceived 
content. Thus a child who is familiar with balls* is shown an 
apple, which, due to his past experience, he calls a ball. From 
the point of view of pedagogy it is probably important to stress 
separately the apperceived and the apperception mass, but 
psychologically the description is unwarranted. Meaning is 
not waiting in consciousness to pounce upon and interpret new 
experiences. Each experience enters consciousness with a 
meaning just as it enters with intensity, quality, and duration. 
The neural process is about as follows: The nervous processes 
produced by earlier experiences have left traces in the synapses. 
When a new nervous impulse comes into any center of the brain, 
it is modified by the retained effects of previous excitations, 
the result being a state of consciousness with a certain meaning. 
The fusion of present activities and traces of past activity does 
not occur in consciousness, but outside of consciousness in the 
nervous system. At present psychologists make little or no 
use of the term apperception. 

The Development of Sensory Processes with Experience. — 
Sensation and perception develop with experience. This 
change may be thought of in two ways: (i) there is a growth 
in the meaning of the conscious state, and (2) the individual 
becomes more sensitive to those stimuli that are affected by 
practice. The lower limit of sensitivity — the magnitude of the 
faintest light, touch, odor, that can be sensed — is termed the 

1 We have here written as though quality were the fundamental char- 
acteristic of sensation and as though the other attributes were attributes 
of it. This is not the usual case. Meaning is the most important attribute, 
as we shall soon see. Furthermore, one may speak as truly of a red intensity 
or duration as of an intense or brief redness. 



SENSORY PROCESSES 219 

lower limen or threshold. Practice affects this so that stimuli 
which before were too faint to be seen or heard now enter con- 
sciousness. This increased sensitivity is not a physiological 
change in the sense-organ, but a change in the nervous centers 
which makes them more easily excited. From the conscious 
side it is referred to as a change in the ease of attending to 
faint stimuli. The growth in meaning that occurs is usually 
different from this change. If two compass points, for example, 
are applied to the dorsal side of an unpracticed observer's 
hand, they may need to be set a centimeter apart in order to 
be felt as two. With practice, however, one comes to attach 
new meaning to slight variations in the contacts, with the 
result that the two-point threshold may be lowered to J cm. 
In general, however, when the topic of the growth of sensa- 
tion is raised, we think of the change of meaning in such 
cases as the growth of significance of pencils, tables, machines, 
houses, books, etc. We never encounter things devoid of all 
significance. The case may be that of a child's meeting a new 
machine. The machine has at least the meaning "something" 
or "funny thing." As the child works with it and learns its 
parts, assembles and knocks it down, sees it run, he is constantly 
securing new sensations, all of which are becoming associated 
and bound together. Now when he meets the machine it is 
no longer "funny thing"; it is "a thing with wheels" or "an 
object to be shown to strangers." Thus the perception has 
developed by an accretion of meaning. On the neural side 
activities in various portions of the brain have become asso- 
ciated with that in the occipital lobe (due to the vision of the 
object) so that the nervous impulse irradiates out into them 
from this lobe as a center. If the irradiation is toward the 
tactual center, the object may mean "heavy thing"; if to the 
auditory center, it may mean "an object that makes a certain 
sound." In every case of sensation and perception this brain 
process of irradiation is present. I see an object as a cold, 



220 GENERAL PSYCHOLOGY 

heavy object, although cold and heavy are not qualities of objects 
which affect the eye but are ones which affect the skin and 
muscles. This is a case where brain centers other than the 
visual supplement the total nervous activity and produce a 
state of consciousness similar to that which we have just 
described. 

The Nature of Meaning. — The foregoing two sections have 
already described many important features of meaning. Mean- 
ing on the mental side is the relationship which one state of 
consciousness bears to others. It is very largely dependent 
upon experience. When, however, reference was made to the 
original stimuli for instincts and emotions, we were dealing 
with innate, non-acquired meanings. On the neural side mean- 
ing is the co-ordination of nervous activities by virtue of which 
a definite response is called forth in muscles and glands. Neuro- 
logically, to the chick the grains of food mean something to be 
pecked, and any small object may mean the same response. 
Furthermore the development of an instinct on its afferent, 
or sensory, side is, as we have already described it, a develop- 
ment of meaning looked at physiologically. When these neural 
processes are of a certain kind or of a certain intensity (when, 
as we say, they cross the threshold or lower limen of conscious- 
ness), the attribute of meaning appears in consciousness. 

Not only is meaning a general characteristic of conscious- 
ness, but it is perhaps the most important of all the attributes 
of conscious states, because it is the conscious representative of 
those neural connections which most intimately determine the 
reactions of the organism. If the meaning that attaches to the 
perception "table" is "support-for-books," placing books upon 
it will be the response I make or plan to make. If I am accus- 
tomed to perceive a chair with the meaning "object-to-be-sat- 
upon," it will be difficult for me to react to it as to a table 
because it is only with difficulty that that meaning will attach 
to it. Meaning is of great importance, therefore, from the 



SENSORY PROCESSES 221 

standpoint of behavior. It is also of great importance from 
the standpoint of consciousness. Practically all tables that I 
see are rectangular. I see them as rectangular, and yet perhaps 
never have I actually seen the table when the angles truly 
subtended at my eye were not oblique. Again, as a person 
walks toward me his apparent size constantly increases, and as 
he walks away it diminishes. These changes in the size of the 
object mean a change in distance, and the changes come to 
consciousness in this form. I actually do not see the variation 
in size; I see the meaning. These are sample cases where the 
meaning of the perception (and the same is true of sensation) 
overshadows its other attributes. I regard the above rectangu- 
lar table, for example, as brown in color-quality, and yet the 
actual color I see varies constantly with the angle from which 
I observe it, with its distance, with the intensity of light, and 
with various other factors. Bishop Berkley (17 10) and Thomas 
Reid (1764) were the first psychologists to stress this point. 
These instances are cases of "standardized meanings." It is 
these standardized meanings, these results of fixed neural con- 
nections, that common sense calls the real object and by which 
it governs its responses. For the common man the table is 
brown and is rectangular, and he so treats it. 

The Classification of Sensations. — -When we are discussing 
sensations we are considering a group of conscious states that 
are literally as different as black is from white or as sweet from 
sour, and yet that all possess the general characteristics of 
sensations. We shall find it profitable, therefore, to consider 
briefly the question of classes of sensations. 

There are many different classifications of sensation, all of 
which are valuable but no one of which is thoroughly satis- 
factory. Hearing, kinaesthesis, touch, and the static sense are 
often referred to as the mechanical senses inasmuch as they are 
aroused by mechanical stimuli. Taste, smell, and vision are, 
then, the chemical senses. Pain will fall under either grouping 



222 GENERAL PSYCHOLOGY 

because it is called forth both by mechanicaland by chemical 
action. Cold, warmth, and the organic sensations cannot be 
definitely placed in this scheme. Opposed to this method, 
common sense groups sensations upon the basis of the apparent 
sense-organ involved: vision, hearing, touch (all sensations 
from the skin), taste, and smell. The grouping in this form is 
inadequate for at least two reasons: (i) it is superficial and does 
not get at all of the sense-organs; and (2) it passes over the fact 
of fundamental biological value that certain sensations are 
aroused by objects that act from a distance, certain others by 
objects that act upon contact with the body, and by still others 
that are effective within the body. Psychology points out that 
there are four kinds of sensations from the skin — cold, warm, 
pain, and contact — with separate end-organs for each. It 
advances evidence indicating that taste is a name for four 
senses — sweet, salt, sour, and bitter — and that vision and hear- 
ing themselves may each be names for two senses. 

The most satisfactory classification (a scientific adaptation 
of that of common sense) is based upon the differences between 
receptors, proposed by Sherrington. 1 In its essentials it is as 
follows: 

1. Proprio-ceptors — receptors lying between the external 
surface of the body and the internal surface (alimentary tract) 
and chiefly located in the muscles, joints, tendons, and semi- 
circular canals of the ear (static sense). The stimuli involved 
are due to the organism's own activity, muscular and glandular. 

1 Titchener has proposed that sensations be classified upon the basis 
of "introspective similarity," a classification from the standpoint of con- 
sciousness rather than of behavior. Red is said to "feel" more like green 
or black than like sour or pain. It is said that we are able to pass from red 
to any other visual quality gradually, whereas we cannot do this from red 
to sour. Although the problem is too large for discussion in an elementary 
text, we may point out that it is possible to pass from taste to smell without 
a break on the conscious side, i.e., without the observer knowing which 
sensory quality he is experiencing. So it is possible to pass from touch to 



SENSORY PROCESSES 223 

The conscious qualities that result are largely kinaesthesis, 
pain, and heavy pressures. 

2. Inter o-ceptors — receptors lying along the alimentary tract 
and stimulated by that portion of the external environment 
there included. Taste, thirst, pain, and temperature sensations 
from the stomach are the conspicuous conscious states con- 
cerned. Hunger is partly intero-ceptive and partly proprio- 
ceptive (or kinaesthetic). 

3. Exter o-ceptors — receptors in the external surface of 
the body, stimulated by changes in the outer environment. 
Included here are vision, hearing, smell, and the cutaneous 
senses (contact, cold, warm, and pain). This class is divisible 
into distance receptors and contact receptors. Contact is the 
only extero-ceptor that cannot be a distance receptor. Vision, 
hearing, and smell receptors will each respond to contact- 
stimulation of their gross structure (blows on the head and 
odorous substances in the nose). Pain and temperature 
receptors will respond either to stimuli acting from a distance 
or to those acting in contact with them. 

As a supplement to this classification, it is of much biological 
importance to note that the distance senses have different func- 
tions as a result of the kinds of stimuli which affect them. One 
of these stimuli, light, is transmitted only in a straight line. 
Vision is therefore the sense best suited to spatial discrimina- 
tion, i.e., to the perception of size, form, and distance. The 
other stimuli of heat, odor, and air-vibrations (hearing) will 
bend around intervening objects. They are, therefore, not 



kinaesthesis; from nausea to taste and pain; and from many other classes 
of sensations to other classes without the observer's being able to detect 
a break in the continuity of the transition. Furthermore, it is certainly 
open to serious question whether red is more like green or black more like 
white than either quality is like sweet or sour. The apparent differences 
are largely due to different meanings and settings of the experiences and 
not to variations in the magnitude of qualitative differences. 



224 GENERAL PSYCHOLOGY 

suited to give an accurate report of the space characteristics 
of an object, but they find their great value in acquainting the 
organism with the presence of objects which are not in an 
unobstructed straight line from the sense-organ. In this way 
food, mates, and enemies are detected, although they may be 
screened from view. It is to be borne in mind that sense- 
organs, receptors, are structures in the body which have been 
developed and specialized with a view to making it possible for 
the animal to react to certain forces in its environment. They 
are the places on the organism that are particularly sensitive 
to light, sound, heat, and other stimuli. Many forces, such as 
X-rays and ultra-violet light, do not in nature stimulate the 
human organism, because there are no receptors adjusted to 
them. It is an open and possibly an unanswerable question 
whether man could adjust himself to his environment better 
if he possessed receptors for those forces which are not now 
effective. 

Sensory Qualities.— The problem of sensory qualities is 
the central problem in sensation. What are the simple odors, 
the simple colors, the simple tones? What are the variations 
in the consciousness of these sensations which result from 
changes in their stimuli? What, for example, is the result in 
consciousness of combining sweet and salt solutions? What 
are the sense-organs underlying those sensations, and what 
processes occur in them as conditions of the states of con- 
sciousness concerned? What goes on in the eye that results 
in a sensation of red? In no case can this last type of question 
be answered by direct observation as one would observe a 
process under the microscope, for one can only infer what 
processes go on in the sense-organs from the nature of the 
states of consciousness which the subject experiences. This 
will be clear as our account proceeds. From the standpoint 
of behavior the analysis of sensory processes is a study of those 
aspects of the stimulus which can arouse muscular and glandular 



SENSORY PROCESSES 225 

activity. Quality is one important aspect. From the stand- 
point of consciousness the analysis of sensory qualities is funda- 
mental because most, if not all, other states of consciousness 
are reducible to these elemental qualities. 

Taste. — The elementary qualities of taste are sweet, sour, 
salt, and bitter. In the past, alkaline and metallic were 
included also; but the former can be produced by a mixture 
of sweet and salt or of sweet and bitter, and the latter by a 
mixture of salt and sour. In everyday experience many more 
"tastes" are recognized. These "tastes," however, not only 
are mixtures of the above elemental tastes, but also include 
touch, temperature, smell, and kinaesthesis. Thus an integral 
part of toast is its crispness (touch and kinaesthesis), and the 
chief part of the "taste" of coffee is its temperature and odor. 
It is this odor component of so-called tastes that is the most 
surprising, for substances which are ordinarily considered to 
possess gustatory properties, if applied to the tongue when the 
nostrils are plugged, are often found to be tasteless. 

The following important phenomena lend support to the 
hypothesis not only that sweet, salt, sour, and bitter are the 
elemental taste qualities, but also that each may be served by a 
separate kind of end-organ. In this case taste would be a term 
covering not only one but four different sense-fields. (1) Sweet 
and salt have the lowest limen at the tip of the tongue. Sour 
is best sensed on the sides and bitter at the back of the tongue. 
(2) Small areas of the tongue can be found that will respond 
with only one quality (sweet, for example); others with two, 
three, or four qualities. (3) Certain substances have one 
taste on one part of the tongue and another on another part. 
Thus, saccharine tastes sweet on most of the tongue but tastes 
bitter at the back. (4) Certain drugs act selectively upon the 
different taste processes. A 10 per cent solution of cocaine, if 
applied to the tongue, will anaesthetize it (render it insensitive) 
first to bitter and then, as the application continues, to sweet, 



226 GENERAL PSYCHOLOGY 

salt, and sour. Gymnemic acid destroys sweet and bitter, but 
does not affect the other qualities. Such losses of taste are 
termed ageusia. To the extent that these four groups of data 
indicate that sweet, salt, sour, and bitter will vary independent 
of each other, to that extent they indicate the existence of four 
senses rather than of one. 

In addition to the phenomena which we have described, 
those of mixture, contrast, and the lower limen of sensitivity 
deserve notice. Mixture has already been referred to in the 
case of alkaline and metallic tastes, which we found to be com- 
pounds of several of the elementary tastes. By contrast is 
meant that one taste is increased in intensity by virtue of the 
fact that it is experienced simultaneously with, or in immediate 
succession to, another taste. Thus, eating sweets makes one 
particularly sensitive to acids and salts. Copper sulphate on 
the tongue makes cigar smoke taste sweet. Bitter is the 
least affected of the four taste qualities. The most striking 
case of contrast occurs when the two substances are applied 
simultaneously to opposite sides of the tongue. If a salt solu- 
tion too weak to be tasted as salt is placed upon one side of the 
tongue and a mediumly strong sugar solution is placed upon 
the opposite half of the tongue, the salt will be sensed. It is 
interesting to note in this connection that the two halves of 
the tongue are supplied with nerves from opposite sides of the 
brain; consequently the two chemical processes and the two 
nervous processes cannot interact in the tongue. With refer- 
ence to the third phenomenon mentioned above, notice can be 
taken only of the fact that the thresholds are increasingly 
higher for bitter, sour, salt, and sweet in that order. Many 
substances such as cranberries taste sweet, but if a drink of 
water is taken a bitter taste is left. The water has weakened 
both the sweet and the bitter, but inasmuch as the tongue is 
much more sensitive to bitter than to sweet, the former still 
affects the sense-organs after the sweet has gone. 



SENSORY PROCESSES 



227 



The sense-organs for taste are ciliated cells contained in the 
taste-buds that line the walls of the crevices of the tongue 
(Fig. 36). In adult humans these taste-buds are found only 
on the upper surface of the tongue (the middle excepted), in 
the soft palate, and on the posterior side of the epiglottis, while 
in children they are also found in the cheeks and on the middle 
of the tongue. In fish, taste-buds are often found scattered 
over the external surface of the body and on the barbules. 
Taste in man is supplied by the Vllth and the IXth cranial 




m\ 






Fig. 36. — A section through a papilla of the human tongue. 1 is 
the papilla; 3 is the taste-bud (after Cunningham). 



nerves. The cortical center is not definitely known but is 
probably near the hippocampus. The stimulus for taste is in 
liquid form, thus facilitating its access to the receptors. 

Smell. — It has already been pointed out that taste and smell 
are so closely related that it is often impossible to distinguish 
between the feel or quality of a complex taste and that of a 
smell. The similarity is equally prominent on the behavior 
(objective) side. The essential sense-organs for smell are 
ciliated cells in the mucous membrane of the nose, differing 
from the taste-cells in that they are cell-bodies of neurones, 



228 



GENERAL PSYCHOLOGY 



whereas the taste-cells are receiving structures only. Figure 37 
shows the area in the nose supplied by the olfactory, or 1st 
cranial, nerve. 

Parker and Stabler have made tests upon the relative sensi- 
tiveness of taste and smell with ethyl alcohol as the stimulus 
for each sense. The results indicated that smell is approxi- 
mately 24,000 times more sensitive than taste. It is essen- 
tially a. distance receptor for stimuli that bend. Although the 




Fig. 37. — The distribution of the olfactory nerve in the nasal cavity 
as it comes from the olfactory bulb, which is attached to the lower portion 
of the frontal lobe of a cerebral hemisphere (from Herrick after Wood) . 



stimulus for smell is usually said to be odorous particles in 
gaseous form, Parker and others have shown that fish have the 
sense of smell, and it is known that the olfactory membrane in 
man is constantly bathed in mucus. It is therefore quite 
probable that the stimulus in each sense is a liquid, and that 
the two senses differ essentially only in degree of sensitivity. 
Opinion is divided upon the relative priority of the two in 
animal development 



SENSORY PROCESSES 229 

So far experiment has presented less evidence that smell is a 
term applied to several senses than we found in the case of taste. 
In neither instance does the microscope reveal different classes of 
ciliated cells. Those for smell are uniform, and so are those 
for taste. Classifications of odor qualities, however, are a step 
on the conscious side toward the discovery of the simple ele- 
ments of smell if they exist. Additional facts are gleaned from 
cases of partial loss of power to smell (anosmia) and from 
studies of olfactory fatigue. In these instances, due to acci- 
dent or to laboratory conditions, certain odors fail to stimulate 
the receiving organs, and as a result the sensations derived from 
many other odors are modified. Fatiguing the olfactory mem- 
brane for iodine, for example, will, according to Arnsohn, 
destroy the power to smell alcohol, heliotropine, and other 
odors; it will weaken the odor of hyacinth, oil of mace, oil of 
citron; and it will either strengthen or leave unaffected ether 
and other odors. It is by tests of this type that it is possible 
to determine the components of complex odors; because, if 
X is exhausted and the complex XY is then presented, X cannot 
be smelled and so only Y remains. Further evidence on the 
existence of elemental odors is gained from observing how 
certain odors change in character as one smells them until 
complete fatigue results. It seems probable that these changes 
are due to the successive fatigue of component odors. 

The study of smell has been carried out largely with th e 
olfactometer (Fig. 38). The principle of the apparatus, which 
is due to Zwaardemaker, is that the intensity of the odor in 
question is proportional to the area of the odorous surface which 
extends beyond the glass tubes shown in the figure. The follow- 
ing phenomena are the chief ones observed in studies with this 
apparatus. If one odor is conducted to one nostril and another 
to the other nostril, either of three results may be secured: the 
odors may mix and give rise to a new odor; they may cancel 
each other so that no odor is sensed; or they may alternate in 



230 



GENERAL PSYCHOLOGY 



consciousness (rivalry). Which result is secured will depend 
partly upon the odors chosen, and partly upon their relative 
intensities. In these cases where the two odors are conducted 
to different nostrils, it is of interest to note again that they 
affect nerves which are interconnected only in the brain. No 
fusion in the sense-organ can therefore take place. The "odors" 
of everyday speech, like the "tastes," involve the sensory 




Fig. 38. — An olfactometer. The odorous substances are placed in the 
cylinders which slide above the scale. A glass tube projects into each 
cylinder and conducts the odor in varying intensity to the subject's nose. 



qualities of touch and kinaesthesis, because many "odors" 
sting and smart or are soft and heavy, while others produce 
muscular movements of the nose and face. 

Cutaneous Sensitivity. — There are four distinct senses whose 
receptors lie either in the skin or just beneath it: cold, warm, 
touch, and pain. Figure 39 shows the types of receptors 
involved. The bulb of Krause is the receptor for cold; the 
end-organ of Ruffini mediates warm; pain is served by the free 



SENSORY PROCESSES 



231 





Fig. 39. — Types of cutaneous and kinaesthetic receptors (from Morris 
and Quain). A, end-organ of Ruffini; B, end-organ of Krause; C, Meiss- 
ner's corpuscle; D, Pacinian corpuscle; E, nerve ending in a muscle. 



232 



GENERAL PSYCHOLOGY 



nerve endings; and the receptors for touch are Meissner's 
corpuscles, the nerve endings at the roots of the hairs, and the 
Pacinian corpuscles. In each case, with the exception of that 
of pain, the receptor is a structure in which the dendrite of the 
sensory nerve begins. The determination of the different end- 
organs is aided by the fact that they are variously distributed 
over the body. The free nerve endings are particularly 
numerous in the cornea of the eye (the clear surface covering 
the iris and pupil), and this area is very sensitive to pain. On 
the other hand an area on the inside of the cheek lacks these 



C 



W 



• « 
• * • • 



• • • « * 

• • «, • • • 



• « 



Fig. 40. — Cold, C, and warm, W, spots on the dorsal surface of the 
forearm (after Goldscheider). 



fiber endings, and no pain can be produced there. The end- 
organs of Krause are especially numerous on the inner surface 
of the eyelids, on the white of the eye, and on the forehead, 
and these areas are particularly sensitive to cold. Likewise 
along with the delicate sensitivity of the finger-tips to contact 
goes an increased supply of Meissner's corpuscles. 

Common sense assumes that the entire skin is sensitive — • 
an assumption that is made partly because the objects of every- 
day life usually stimulate large areas on the surface of the body. 
If the skin is explored point by point, however, it is found that 
only certain points will respond with sensory qualities. Figure 
40 shows a map of this punctiform distribution of sensitivity 
as prepared by Goldscheider. It will be seen that the numbers 



SENSORY PROCESSES 233 

of cold and warm 1 spots vary even on a small area. Experi- 
menters have estimated that there are from 2,000,000-4,000,000 
pain spots on the body, 500,000 each of cold and touch, and 
30,000 warm spots. The hairs scattered over the body act 
as levers to increase the force of pressure on the skin and also 
serve to decrease the area stimulated, thus making the skin 
more sensitive, i.e., lowering the threshold of sensitivity. 

The stimulus for touch, however, is not merely mechanical 
pressure on the skin, for if the hand is inserted in water of body 
temperature or in mercury, for example, pressure is felt only as 
a ring at the upper level of the fluid. Accordingly a pressure 
gradient from low to great intensity, such as that which occurs 
around the edge of an object pressing upon the skin, constitutes 
the stimulus for touch. The stimulus for warm and cold is 
involved in too much controversy to be presented here. It is, 
however, bound up fundamentally with what is termed the 
physiological zero. The physiological zero is the temperature 
to which any particular area of the skin is adapted, i.e., tempo- 
rarily insensitive, the limits within which this may occur being 
usually given as n°-39° C. Any increase in temperature 
above the momentary state of adaptation is felt as warm, any 
decrease as cold. By passing gradually from one temperature 
to a higher or lower and allowing the skin to adapt at each point, 
it is possible to do severe injury to the organism without its 
being aware of the fact. 

The stimuli for pain may perhaps be generalized as "injury 
to the body," although much injury in the way of tumors and 
cancers involves no awareness of pain. Pain receptors are 
often termed noci-ceptors. At a certain intensity all stimuli 
affect the noci-ceptors and are felt as pain. The rate at which 
the increase in intensity occurs is an important condition of the 
phenomenon. Sudden heat will cause pain, but the same 

1 The sensation of heat arises from the simultaneous stimulation of cold 
and warm spots. 



234 GENERAL PSYCHOLOGY 

temperature gradually attained will not. Slow pressures, on 
the other hand, will cause intense pain, whereas the rapid 
pressure of a knife or bullet may cause none. It is also of 
interest in this connection to note that the nervous impulses 
underlying emotion block, more or less perfectly, those for pain. 
Thus persons may sustain severe wounds during emotional 
excitement in ignorance of their occurrence. Injury to the 
viscera apparently causes no pain unless the peritoneum is 
involved. Noci-ceptors are undoubtedly stimulated in these 
cases, but the nervous impulses fail to reach the cortex and 
accordingly do not condition consciousness. 

Because of the correlation of pain and injury, the subject 
is of great importance in medicine. On page 77 reference has 
already been made to the loss of pain (analgesia) in hysteria. 
At this point brief mention is to be made of propagated pains, 
instances where pain is not localized at the seat of injury and 
stimulation. There are two classes: referred, or projected, pains 
and associated pains. The former are those pains which are 
located at the terminus of the nerve although the injury is to 
the nerve trunk. Pains felt in an amputated hand (which 
therefore is no longer present) constitute a striking case. Asso- 
ciated pains are located in the terminus of one nerve, whereas 
the injury is at the terminus of another. This results from a 
transfer of the nervous impulse from one pathway to another 
within the central nervous system. One may have severe 
abdominal pains from eye strain; pain in the forehead from 
eye defects; pain in the knee from toothache or hip-joint 
trouble; pains in the head from intestinal and uterine disturb- 
ances, etc. The faulty localizations that are characteristic 
of associated pains are due to the excitation of brain areas that 
are normally aroused only by impulses from the peripheral ends 
of certain nerves. If these impulses begin midway of the nerve 
or are switched in over it, the brain center responds as usual, 
and the pain is located in accordance with the brain's normal 



SENSORY PROCESSES 235 

response. The result is a mislocation such as we have described 
in the instances above. 

Since 1905 there has been a well-defined tendency to regroup 
cutaneous sensitivity, as we have described it, into epicritic 
and protopathic with an additional subcutaneous class of deep 
sensitivity. This classification was proposed by Head and 
Rivers on the basis of experiments performed upon Head 
himself. After cutaneous sensitivity over a certain area of the 
hand and forearm had been carefully tested, the sensory nerve 
which supplies that area of the skin was cut and the ends care- 
fully sutured together. As the nerve regenerated, careful 
studies were made of the sensitivity of the abnormal skin area. 
The following results were secured: (1) Deep sensitivity was 
not disturbed by the operation. Here belonged heavy pressure 
and dull pain localized deep in the tissue. These sensations 
were accurately localized by Head. (2) Protopathic sensi- 
tivity (called by these students the primitive cutaneous sensi- 
tivity) remained in certain areas where the epicritic was gone, 
and in those areas where both were destroyed it reappeared 
first. It included sensations of extreme cold and warm and 
medium intensities of touch and pain, all of which were diffuse 
and poorly localized. (3) Epicritic sensitivity (light touch, 
slight changes in temperature, and pain) was the last to return. 
These sense qualities were well localized. In addition to the 
original observations other investigators, notably Franz and 
Boring, have studied the question and have secured data con- 
firmatory in general of the facts given above. Much other 
material that Head offers, however, cannot be accepted at 
present. 1 

Kinaesthetic and Organic Sensations. — Kinaesthetic sensa- 
tions are derived from the muscles, joints, and tendons. In 

1 Upon the variations in sensory consciousness here described, Head 
proposes a radical modification in current conceptions of the cutaneous 
nerve supplies. 



236 GENERAL PSYCHOLOGY 

daily life these sensations are always associated with cutaneous 
sensations due to the stretching and relaxing of the skin during 
muscular responses. However, close attention to muscular 
strain, such as is found in lifting an object or in lifting and then 
suddenly releasing it, will familiarize the reader with the par- 
ticular quality of these sensations. Their great tendency to 
fuse with cutaneous and organic sensations has impeded their 
study from the conscious side, though as a part of these com- 
plexes they are studied in emotion and affection. On the 
behavior side it seems certain that the sensory impulses arise 
from Pacinian corpuscles and from nerve endings in the muscles, 
and that they are fundamental in guiding movement and in 
maintaining bodily equilibrium. Wherever a series of muscular 
movements (walking, writing, talking) occurs, the kinaesthetic 
impulses set up by one movement are important parts of the 
stimuli for the next movement. It is thus that we traced the 
connection between successive reflexes in the discussion of 
instinct. In studies of animal behavior when the animal can 
be shown to solve a problem without the aid of vision, hearing, 
touch, taste, or smell — as may be the case in maze habits — 
the only remaining possibility is kinaesthetic and organic 
sensitivity. Much of the little that is known concerning 
these sensory processes is, therefore, derived from this field of 
learning. 

It is not definitely known what the receptors for organic 
sensations are. These sensations are aroused by muscular and 
glandular activities and function during emotions, affective 
processes, feelings of bodily existence, bodily well-being, and 
other similar conscious states. Specific combinations or fusions 
of these sensations occur in emotion, while other equally striking 
ones occur in connection with the activity of the alimentary 
canal (food) and with the reproductive organs (sex) when 
emotions are either faint or absent. Hunger, thirst, and satiety 
are terms applying to some of these sensations. Of these 



SENSORY PROCESSES 



237 



hunger has been extensively examined of late by Cannon, 
Boring, and Carlson and may well receive special mention here. 
As a state of consciousness hunger, in its mild form, is a 
vague pressure-sensation referred to the region of the stomach, 
while in intense hunger diffuse pain is added to the pressure. 
In either case the pangs of hunger are intermittent. In persons 
who are fasting, the hunger-sensations disappear after the third 
or fourth day and do not thereafter return. Death from 




Fig. 41. — "Diagram showing method of recording gastric hunger 
contractions of the empty stomach of normal persons. B, rubber balloon 
in stomach. D, kymograph. F, cork float with recording flag. M, ma- 
nometer. L, manometer fluid (bromoform, chloroform, or water). R, 
rubber tube connecting balloon with manometer. S, stomach. T, side tube 
for inflation of stomach balloon" (from Carlson). 



starvation, so far as the pangs of hunger are concerned, is 
apparently a mild termination to life. 

The most interesting experiments recently have been 
directed toward an analysis of the stimulus to hunger. A small 
rubber balloon is attached to a stomach tube and is then swal- 
lowed. The balloon is inflated sufficiently to fill the empty 
stomach, and the free end of the rubber tube is attached to a 
tambor whose marker writes upon a smoked drum (Fig. 41). 



238 GENERAL PSYCHOLOGY 

Whenever the stomach contracts, a puff of air is transmitted 
to the tambor, and the marker records on the surface of the 
drum. The subject who has swallowed the balloon has a signal 
key attached to another marker by means of which he can 
record on the drum when his hunger pangs appear and the 
extent of their duration. In addition a record of breathing 




Fig. 42. — "One-half the original size. The top record represents 
intragastric pressure (the small oscillations due to respiration, the large 
to contractions of the stomach); the second record is time in minutes 
(ten minutes); the third record is W's report of hunger pangs; the lowest 
record is respiration registered by means of a pneumograph about the 
abdomen" (from Carlson). 

and a time-record in seconds are registered on the drum. These 
various data are shown in the sample given in Fig. 42. It will 
be seen that the pangs of hunger are paralleled by the stomach 
contractions — a condition which has been so extensively con- 
firmed by Carlson and his students that it may be regarded as 
an established fact that the stomach (and probably the oesopha- 
geal) contractions are the stimuli for hunger. The nerve 



SENSORY PROCESSES 239 

involved is the Xth cranial nerve, the vagus. The cortical 
center is probably the post-Rolandic area, although some evi- 
dence points to the hippocampus. Physiological changes in 
the blood and the absence from the stomach of material whose 
presence has inhibited the contractions are probably the 
stimuli which in their turn arouse the stomach contractions. 



REFERENCES 

Boring, E. G. "The Thermal Sensitivity of the Stomach," Amer. 

Jour. Psych., XXVI (1915), 485-94. 
. "Cutaneous Sensation after Nerve Division," Quar. Jour. 

Exper. Physiol., X (19 16), 1-95. 
Cannon, W. B. Bodily Changes in Pain, Hunger, Fear, and Rage. 

New York: 191 5. 
Carlson, A. J. The Control of Hunger in Health and Disease. 

Chicago: 191 6. 
Carr, H. A. "Head's Theory of Cutaneous Sensitivity," Psych. 

Rev., XXIII (1916), 262-78. 
Head, H., Rivers, W. H. R., and Sherren, J. "The Afferent Nervous 

System from a New Aspect," Brain, XXVIII (1905), 99-115. 
and Rivers, W. H. R. "A Human Experiment in Nerve 

Division," Brain, XXXI (1908), 323-450. 
Herrick, C.J. Introduction to Neurology, chap. v. Philadelphia: 191 5. 
James, William* Principles of Psychology, Vol. II, chap. xvi. New 

York: 1890. 
Titchener, E. B. Text-book of Psychology,^. 471-505. New York: 

1908. 



CHAPTER VII 

SENSORY PROCESSES (Continued) 

Auditory Sensations. — Sensations of sound belong to two 
well-marked groups, tone and noise. The tones of daily life 
are complex and may be termed klangs. They are composed 
of a fundamental tone and various faintly sounding overtones 1 
that are higher in pitch. Simple or pure tones relatively free 
from overtones are produced by lightly struck tuning-forks 
and by weakly blown bottles. A sensation of tone is smooth, 
continuous, and usually pleasant as compared with the rough- 
ness, interruptedness, and usual unpleasantness of noise. 

Tones are classified on the basis of pitch from low to high. 
As a rule they occur accompanied by noise, although under 
careful laboratory conditions pure tones may be produced. 
Noises are classified as continuous, interrupted, and as beats 
(see p. 246). They are probably always accompanied by 
tone by virtue of which they appear high or low. We have so 
little information about noise that it is even uncertain what 
part of the ear is concerned. There is, on the other hand, a 
voluminous literature on tone-sensations and their combina- 
tions. Tone has three specific attributes: quality, or pitch, 
timbre, and intensity. The timbre, which is often called tonal 
character, is that which distinguishes a given tone on one instru- 
ment, a piano, for example, from the same tone on another 
instrument. We shall have more to say concerning these 
attributes in the following pages. 

Stimuli and Receptors. — The stimuli for both classes of 
sound-sensation are air-waves. Disturbances in the air may 

1 Practically all sounding bodies vibrate in parts or segments as well 
as in wholes. The tones corresponding to these partial vibrations are 
overtones. 

240 



SENSORY PROCESSES 241 

also stimulate touch and, indirectly, temperature receptors. 
However, when the alternate condensation and rarefaction set 
up in the air by a vibrating body equal or exceed approximately 
16 per second the sound receptor (the ear) is stimulated. This 
vibration-rate is the lower limen for pitch-discrimination. 
When the frequency of the air-vibration exceeds approximately 
50,000 per second it ceases to affect the ear, and we have the 
upper limen for pitch. In between the two limens there are 
some 11,000 discriminable pitches. If the air- vibrations are 
periodic, and if at least two complete vibrations occur, the result 
in consciousness is tone. If, on the other hand, the air- 
vibrations are aperiodic and heterogeneous, or if less than two 
complete air-waves strike the ear, the result in consciousness is 
noise. The pitch of a tone is determined by the frequency of 
air- vibration; the intensity, by the amplitude ; and the timbre, 
by the form of the vibrations (see Fig. 45, p. 247). The form 
of the vibration is determined by the number and relative 
intensity of the overtones. We are to understand, therefore, 
that the middle C, 256 d.v. (double or complete vibrations), on 
a piano differs from that tone on any other instrument primarily 
by virtue of other fainter pitches (overtones) that accompany 
it and that do not accompany the others. By combining various 
fundamentals and overtones Helmholtz was able to match the 
tones of the chief musical instruments. 

The essential end-organ for tone is the hair cells in the 
cochlear canal of the ear where the auditory branch of the 
Vlllth cranial nerve terminates. The cortical center is in 
the superior, or upper, portion of the temporal lobe of the 
cerebrum. Prevailing opinion applies the same statements 
to noise, although it is not certain that noise may not at least 
be partly conditioned by activities in the saccule and the 
utricle (structures in the inner ear). 

The reader must rely upon a study of models and upon his 
instructor's presentation for a knowledge of the anatomy of 



242 



GENERAL PSYCHOLOGY 



the ear. Figures 43, 44^4, and 44B will, however, if carefully 
studied, give much preparatory information. The semi- 
circular canals, saccule, and utricle, whose locations are shown 
in the accompanying figure, are connected through the vestibular 
branch of the VHIth nerve with the cerebellum. They func- 
tion in aiding the maintenance of bodily equilibrium and 

Tympanic cavity, with chain of ossicles 
Semicircular duct 
Utricle 
Ductus endolymphaticus 
Saccule 
Ductus cochlearis 




mm- Auricula 



Auditory tube 

Membrana tympani 

Recessus epitympanicus 



External acoustic meatus 



Fig. 43. — A diagrammatic view of the ear (from Cunningham) 



constitute the receptors for the static sense. The canals are 
particularly active in rotary motion, and the saccule and utricle 
are probably active in motion in a straight line. In either case 
the motion of the body stimulates small sensory patches in the 
structures mentioned, the immediate stimulation being due 
to the inertia of the fluid and calcareous particles found in 
those receptors. When the body moves, these particles lag 





B 

Fig. 44. — A, typical cross-section of the cochlea (from Calkins after 
Foster). Sc. V. is the scala vestibuli, shown in black above the cochlear 
duct in the preceding figure; m. R., Reissner's membrane; C, CM., coch- 
lear duct, or canal; m. b., basilar membrane; m. t., tectorial membrane; 
Org. C, organ of Corti; Sc. T., scala tympani; n. aud., auditory nerve; 
Gg. sp., spiral ganglia containing the cell-bodies of the neurones making 
up the auditory nerve. 

B, a cross-section of the cochlear duct of a pig showing: HT, tectorial 
membrane; hair cells and rods of Corti just below and resting upon BM, 
the basilar membrane. Notice that this membrane has a layer of cells 
on each side of it which would interfere with its free vibration. R is Reiss- 
ner's membrane. The fibers of the auditory branch of the Vlllth nerve 
pass through the region marked N (modified after Hardesty). 



244 GENERAL PSYCHOLOGY 

behind and in this way affect the receptors. The three struc- 
tures we have mentioned are termed the vestibular portion of 
the ear. Chief interest, however, centers upon the auditory 
portion of the ear, which we shall now consider. 

Air-waves pass down the external acoustic meatus and set 
the tympanum (ear drum) in vibration. These vibrations are 
transmitted by the three bones of the middle ear (hammer, 
anvil, and stirrup) to a membranous window leading into the 
inner ear. Here the vibrations proceed through a liquid, 
endolymph, in the scala vestibuli for a short distance; or if the 
vibration is intense they may pass to the end of this passage. 
In their course onward the vibrations are transmitted through 
Reissner's membrane into the scala tympanum and so finally 
spend themselves in the vibrations of a membranous window 
(the round window) opening back into the middle ear. Certain 
structures in the cochlear canal are thrown into vibration, thus 
starting activities in the hair-cells. By this means a nervous 
impulse is initiated in the fibers of the VIHth nerve which then 
passes to the central nervous system. Although the preceding 
account is fairly complicated, it is absolutely essential if even 
the rudiments of the ear's activity are to be understood. 

Theories of Hearing. — Theories of hearing deal with the 
probable activities in the cochlear canal which underlie the 
consciousness of various sound phenomena (tone, noise, beats, 
combination tones, melody, etc.). Some of these phenomena 
we are soon to describe briefly. The most conspicuous theory 
that we have was advanced by Helmholtz. He assumes that 
the basilar membrane is composed of transverse fibers keyed 
to different pitches. These fibers are supposed to respond by 
sympathetic resonance to vibrations in the air and endolymph 
much as one tuning-fork will sound when another of the same 
pitch is active in its immediate vicinity. The vibration of the 
fibers of the basilar membrane stimulates the hair-cells, and in 
this way the nervous impulse is started. In support of this 



SENSORY PROCESSES 245 

theory it is known that there are transverse fibers of various 
lengths in the basilar membrane, and there is some evidence 
indicating that the broad end of the membrane subserves tones 
of low pitch. The chief objection to the theory, however, 
is anatomical, for the transverse fibers are not free to vibrate, 
but are interlaced with longitudinal fibers and covered on both 
sides with cell-layers as shown in Fig. 44^. . Against this fact 
the simplicity of the theory should have no weight. 

Recently (since 1905) Shambaugh and Hardesty have pre- 
sented important contributions indicating that the tectorial 
membrane is the structure which by vibrating stimulates the 
hair-cells. Hardesty has constructed a large model of the 
cochlear canal and has shown that an artificial tectorial mem- 
brane will be set in activity by vibrations in the air and endo- 
lymph. Ewald has presented similar evidence indicating that 
the basilar membrane may be set into activity in ways other 
than that described by Helmholtz. However, the anatomical 
measurements made by Hardesty favor at present the major 
influence of the tectorial membrane. 

Certain Problems in Audition. — For man phenomena of 
sound reach their greatest complexity in music. Music may 
be either a rhythmical sequence of related tones (melody) or it 
may in addition involve two or more related tones sounding 
simultaneously (harmony). The chief intervals or relation- 
ships used in modern European music are as follows: 

Octave C:C 1:2 Major Second C : D 8 : 9 

Fifth C:G 2:3 Minor Second. .. .C:|?D 15:16 

Fourth C:F 3:4 Major Seventh ... C : B 8:15 

Major Third C:E 4:5 Minor Seventh ... C : |?B 9:16 

Minor Third C : |?E 5:9 [Natural (subminor) 

Major Sixth C:A 3:5 Seventh 4:7! 

Minor Sixth ,.C:^5:8 Tritone F:B 32:45 

The ratios between the vibration-frequencies of the lower tone 
and those above it are also included here. Any sequence of tones 



246 GENERAL PSYCHOLOGY 

related according to these ratios is experienced as a unit, and 
constitutes a melody. Experiment has shown that a sequence of 
tones must end upon a tone whose vibration-rate is a power of 
two, if it is to constitute a unitary sequence. Thus, consulting 
our table, if we find the interval C:E 4:5 employed, the tone 
E is left suspended, and the sequence feels unfinished until C is 
again sounded. On the other hand if E : C is played, the sequence 
comes to a close, ending on a power of two. Likewise a falling 
inflection is preferred with the fifth and a rising inflection with 
the fourth. This rule of 2 does not explain the phenomena of 
melody; it serves only to classify cases of tonal sequence. Here, 
as is the case with consonance which we are soon to describe, 
many sequences that are at first felt not to be unitary are 
accepted after practice. It is also possible to change the pitch 
of one of the tones, C in the E:C sequence, for example, enough 
so that the ratio is no longer 2:3 and still the sequence is experi- 
enced as a melody. No explanation has been found which 
covers all of these facts. 

In order to state even in the briefest manner the essentials 
of harmony, it is necessary to consider certain elementary 
phenomena that appear when two tones are sounded simul- 
taneously. One of these phenomena is that of beats. Beats 
are variations in the intensity of the tonal experience, their 
frequency being determined by the difference in vibration-rate 
of the two generating tones. This variation of intensity is 
paralleled by an interference of the air-waves as indicated in 
Fig. 45. When beats are slow, from about 1 in 2 seconds to 
a little over 1 per second, they rise and fall gradually with a 
minimum of unpleasantness. As they increase in rapidity up 
to 60 per second, they become more and more sharp and thrust- 
like, finally degenerating into a blur of roughness. Through- 
out the scale of more rapid beats the sound complex is very 
unpleasant. The roughness is more pronounced in the upper 
regions of the pitch scale. In certain instances the beats appear 



SENSORY PROCESSES 247 

to be in one or other of the generating tones, while in other 
cases a tone intermediate in pitch is heard, and it is this tone 
that seems to beat, i.e., to vary in intensity. 

When the difference in vibration-frequency of the two 
generating tones reaches about 80 vibrations per second, a 
third tone is heard which is lower in pitch than either. This 
is the first difference-tone — which introduces us to the next ques- 
tion to be considered in our study of harmony. Its pitch is 
equal to the difference of vibration-frequency of the two primary 
tones. There are at least five combination tones that may be 




Fig. 45. — Interfering air-waves. The amplitude is one-half the dis- 
tance between the top and bottom of the curves. The form of the wave 
is its contour. Wave-length is the distance horizontally between any two 
homologous points on the curve. There are eight complete wave-lengths 
in one of the fainter curves and nine in the other. The heavy curve is 
the result of the combination of the other two. There is almost a can- 
cellation of amplitudes (intensity) in the center of the figure. This in 
comparison with the ends of the curve gives the physical basis of a beat. 

heard by the practiced observer. The formulas by which their 
pitches are calculated are as follows (we shall use C of 512 
vibrations per second and E 640) : 







Vibrations 






PER SECOND 


Dx 


h-l 


640- 512 = 128 


D 2 


2I-I1 


1024- 640 = 384 


D 3 


3I-2I1 


1536-1280=256 


D 4 


4/-3A 


2048-1920=128 


D s 


4A-5Z 


2560-2560 = 



Thus with these two tones the fifth difference-tone would be 
absent, and the first and fourth would coincide. In addition 
to these combination tones, another one, the summation tone, is 



248 GENERAL PSYCHOLOGY 

frequently heard, whose formula is h plus I. In the above 
illustration its pitch would be n 52 vibrations. Combination 
tones and beats are produced, not only between the fundamental 
tones, but between the overtones in klangs. Combination tones 
are of subjective origin, i.e., they are produced by peculiar 
vibrations within the sense-organ, and not by vibrations in 
the air. 

With this preliminary account of the phenomena arising 
when two tones are sounded together we are now able to con- 
sider the question of consonance (harmony) and dissonance. 
Certain tones when sounded simultaneously are pleasing, others 
are less so. The more pleasing ones are the consonances. 
Stumpf would insist that the more consonant intervals are those 
that exhibit the greatest degree of fusion, i.e., those whose 
component tones blend together most perfectly. We know, 
however, that there has been a development in the history of 
music such that combinations of tones which were not at first 
regarded as consonant were later accepted as such. The rela- 
tionships between tones in harmony are the same that we have 
indicated as occurring in melody, although here the tones are 
simultaneous. The harmonic intervals in their order of decreas- 
ing consonance are usually given as follows: octave, fifth, fourth, 
major third, major sixth, minor third, and minor sixth. Such 
a list as this represents the predominant opinion of skilled 
observers who are trained to judge the various intervals on the 
basis of a greater or less consonance. 

Aside from Stumpf's theory referred to above, which holds 
that the essential element in consonance is fusion, the two 
most prominent theories are those of Helmholtz and Kriiger. 
Helmholtz attributes consonance to the similarity or identity 
of the overtones in the generating tones, dissonance being due 
to beats between the overtones or fundamentals of the generat- 
ing tones. Wherever such beats occur, there is dissonance. 
Kriiger bases his theory upon difference-tones. Dissonances 



SENSORY PROCESSES 



249 



are characterized by beating difference-tones and fundamentals 
(mistuned unisons). Consonances lack these disturbances and 




Fig. 46. — Horizontal section through the left eye (from Angell). 
The optic disk is the portion of the retina at the entrance of the optic 
nerve. Pr. cil. indicates the ciliary process or muscle; conj.. conjunctiva; 
rel. y retina; chor., choroid; scler., sclerotic; fov. c, fovea. 



furthermore possess relatively few difference-tones. Perfect 
consonances are rare, but all consonances sound clear, simple, 



250 GENERAL PSYCHOLOGY 

and familiar. It is impossible at present to decide between the 
different theories. We must, however, concede much to each 
of them and also to the effects of practice (Moore) . 

Visual Sensations — -Visual Receptors. — -The essential recep- 
tors for vision are the rods and cones of the retina of the eye. 
Figure 46 represents the eye as a whole and Fig. 47 gives the 
detailed structure of the inner (retinal) coat. Rays of light 
pass through the cornea, lens, vitreous humor, and strike upon 
the retina. This latter, however, is transparent, and the rays 
pass through the ganglion-cell layer, the bipolar layer, the rod 
and Cone layer (shown in Fig. 47), and set up chemical changes 
in the outer segments of the rods and cones. These changes 
start nervous impulses which pass through the layers of the 
retina, out over the optic nerve to the thalamus and the mid- 
brain, and then to the occipital lobe of the cerebrum, if visual 
consciousness is to result. The optic disk, in which are found 
neither rods nor cones but only fibers, is insensitive and gives 
rise to a blind spot in the visual field. 1 The fovea is the retinal 
area of greatest sensitivity. It subtends an angle of 5s'-7o' 
from the nodal point (about the center of the lens) ; or, in other 
terms, it is o. 2-1 . o mm. in diameter. There are no rods here, 
only cones. As we pass to the periphery of the retina from the 
fovea as a center, the rods gradually increase in number rela- 
tive to the cones until on the extreme periphery very few cones 

1 The reader should demonstrate this for his own satisfaction. Take 
two pieces of white paper each 1 cm. square, hold them side by side about 
18 inches from the eyes. Close the left eye and fixate the left paper with 
the right eye. Now gradually move the right paper farther to the right, 
keeping the eye fixed on the stationary one. Soon the right paper will fall 
within the area of the blind spot. By moving the paper about (right to 
left and up and down) the exact outlines of the spot can be found. The 
blind spot is really a blind cone extending into the distance with the apex 
at the eye. Very large objects, if far enough away, will be invisible when 
they come within the cone. To find the blind cone with the left eye, close 
the right eye and fixate the proper object with the left eye. 



SENSORY PROCESSES 



251 



are present. The choroid, which underlies the retinal layer, 
is a black pigmented coat that serves primarily to absorb the 
rays of light, thus preventing reflection within the eye. The 
third and last layer is the sclerotic coat, which is tough, fibrous, 
and practically opaque in man. It serves to hold the eyeball 




Fig. 47. — Diagram of the detail of the retina (from Howell). 1 is 
the choroid coat; 1 neuron includes rods (slender) and cones; 2 neuron 
indicates the bipolar layer; 3 neuron indicates the ganglion cells and their 
axones which go to form the optic nerve. 

in shape and to keep out the light. The adjustment of the eye 
to the location of an object is accomplished by two muscular 
mechanisms: (1) six muscles are attached to the outer surface 
of the sclerotic and serve to move the eye in the socket; and 
(2) the ciliary muscle inside the eye varies the tension on the 
lens, thus flattening it for far vision, or permitting it to bulge 



252 GENERAL PSYCHOLOGY 

for near vision (see Fig. 53, p. 274). The latter muscle is the 
mechanism of accommodation and aids in securing a sharp, 
retinal image of the stimulus upon the retina. Changes in the 
contraction of the muscles of the iris vary the size of the pupil 
and also aid in the formation of a clear retinal image. 

Visual Qualities. — Visual sensations, like those of audition, 
include two qualitative series — the achromatic or brightness 
series of black, white, and the intermediate grays; and the 
chromatic or color series, the elemental qualities of which are red, 
green, blue, and yellow. It is possible to have brightness, a 
gray, for example, without color, but all color involves a bright- 
ness, or intensity, value. As one passes from black through the 
grays to the white, one passes through a series of visual qualities 
each of which can be produced by a combination of black and 
white. The color-sensations are more complex. In the first 
place there are four elemental qualities in place of two, and in 
the second place they possess the attributes of intensity and 
saturation in addition to their hue or quality. The hue is the 
attribute named by language, e.g., red, orange, green; by 
saturation we refer to the purity or depth of the color; and 
intensity, or brightness, indicates the luminous value. These 
three attributes can to a certain extent be varied independent 
of each other. A blue, for example, may be bright or dark and 
yet retain the same saturation, or its saturation may vary while 
hue and brightness remain constant. These relationships are 
clearly symbolized by a figure called the color-pyramid shown 
in Fig. 48, to the study of which the student may well devote 
considerable time in order to gain a thorough understanding of 
many facts in the relationships of color-characteristics. The 
achromatic series is represented by the central perpendicular 
axis. The colors are arranged around the outside of the pyramid 
with the four elementary colors at maximal saturation located 
at the four corners of the base. From the base-line toward 
the top are the tints, or brighter colors, while toward the bottom 



SENSORY PROCESSES 



253 



are the shades, or darker colors. In each case, as black or white 
is approached, not only is the brightness value changed, but 
there is a decrease in saturation. As one passes horizontally 
from a given point toward the black-white line, the hue and 




Fig. 48. — Color-pyramid described in the text 



brightness remain constant, but the saturation decreases. In 
order to change the hue one must pass around the black-white 
line. 

The hue of a color-sensation is correlated with the wave- 
length of the ray of homogeneous light that is stimulating the 



254 GENERAL PSYCHOLOGY 

eye. Its saturation is determined by the purity of the ray, 
i.e., its freedom from light of other wave-lengths, and its bright- 
ness is determined by the intensity of the light-ray. Achromatic 
sensations result from a great variety of causes. Ordinarily 
heterogeneous light-waves, so-called white light, produce the 
qualities of their series by variations in intensity. 1 But under 
certain conditions light of a single wave-length, which would 
ordinarily be seen as red or violet or some other color, will be 
seen as achromatic. These conditions are: very high or very 
low intensity, the rapid alternation of one wave-length with a 
certain other wave-length (called its complementary color) so 
that the two stimulate the same portion of the retina in rapid 
succession, and the stimulation of the eye from the periphery 
of the field of vision. First let us comment upon the effect 
of light-intensity upon hue. If a light-ray of certain wave- 
length (567 fjLfx 2 ) that ordinarily is seen as yellow is started at 
zero and increased in intensity, there will be a certain amount 
of increase before it is seen as yellow. A continued increase will 
make the quality lighter and lighter until all color is lost and it 
becomes white. The same condition holds as the color is 
darkened toward black. The interval between the threshold 
where the light is seen and the threshold where the color is 
seen is called the photochromatic interval (not shown on the 
color-pyramid) which varies in magnitude with the different 
wave-lengths (color-hues). The variations in hue with change 
of intensity are too complex to attempt to represent on the 
pyramid. The second condition for producing achromatic 
light by means of color-stimuli is discussed in the following 
section. 

Color-Mixture and Complementary Colors. — If two disks 
of colors are placed upon a rotating spindle called a color-wheel, 

1 Black, although correlated with the absence of light, is not the absence 
of sensation. It is a genuine sensation quality. 

2 Millionth of a millimeter. 



SENSORY PROCESSES 255 

by rapid rotation they will mix into a third color. For the 
normal human eye any color may be matched by a proper mix- 
ture of red, green, blue, and yellow, e.g., red and blue will give 
purple. On the color-pyramid the character of particular 
mixtures can be determined by taking a point between the colors 
and noting the relative amounts of the hues involved. A 
mixture of a blue tint (point b), for example, and a shade of 
green (point g) will give a poorly saturated blue-green of medium 
brightness (point c). There is one case of color-mixture that 
is of particular importance — -the second of the conditions of 
achromatic vision that we mentioned in the preceding section. 
For every hue some other hue can be found which, when mixed 
with it, will give not a color but a gray. These hues are comple- 
mentary colors. To find the complement of any color by means 
of the color-pyramid, draw a straight line from the point repre- 
senting that color through the base-point of the black-white 
line to its intersection with the opposite surface of the pyramid. 
This intersection point will give the complementary color. 
In Fig. 48 the dotted line shows that a shade of green is the 
complement of a tint of red, r. The lighter grays may also 
be said to be the complements of the darker grays, for a light 
gray mixed with a dark gray will give a medium gray. 

Simultaneous Contrast and After-images. — Every color or 
brightness tends to tinge its surroundings with a quality 
essentially its complement. A white or light object tends to 
darken the surface immediately contiguous to it, and a dark 
object tends to lighten it; or, as we say, each visual quality 
induces its complement in the surrounding field. 1 A red object 
tends to tinge its contiguous objects with a blue-green. In a 
similar manner shadows on snow are blue because of the yellow 
in the sunlight, and the shadows on white paper from a green 

1 The phrasing here is for convenience. One color (sensation) does 
not change the visual qualities that are located contiguous to it. The 
action is in the retina and in the central nervous system. 



256 GENERAL PSYCHOLOGY 

study-lamp can be seen to be reddish. As a result of this 
simultaneous contrast each object tends to take on added 
distinctness. 

After-images 1 are of two kinds, positive and negative. The 
positive after-image has the same hue and brightness as the 
original sensation. The negative after-image is the comple- 
ment of the original sensation in hue and brightness and is an 
instance of successive contrast. If one glances but for a second 
at a red object and then either shuts his eyes or turns them 
quickly to a uniform surface, the positive after-image can be 
clearly seen. It is most evident with unpracticed observers 
when stimuli of high intensity are used, such as the sun or a 
16 c.p. electric light. Carr has recorded a case, however, where 
the individual's positive after-images of mediumly light objects 
were so strong and persistent that the subject could not see other 
objects through them. Shortly after the positive after-image 
fades the negative after-image appears, which, as we have said, 
is the complement of the original stimulus. The student may 
easily experience this phenomenon by looking a few seconds at 
any clear patch of color or brightness, and then fixating some 
uniform surface. 

Peripheral Vision. — The retina is not equally sensitive to 
color throughout its extent. If one fixates constantly a given 
point and moves a small square of red paper from in front of the 
point on out to the limits of the field of vision, the red soon 
ceases to appear red. It may gradually assume a yellow hue, 
and a little farther out it will turn gray — our third condition for 
producing achromatic vision by means of color-stimulation. 
There is a certain red containing just a trace of blue which in 
passing from central to peripheral vision does not change its 
hue but goes directly into gray. Likewise there is a certain 
green, a certain blue, and a certain yellow that pass directly 
into mere brightness. The instrument used in mapping the 

1 They are not actually images, but are after-sensations. 



SENSORY PROCESSES 



257 



extents of these color-zones is termed a campimeter, or perimeter, 
one of which Fig. 49 represents. The data derived from this 
experiment indicate that in all directions from the fovea red and 
green are seen only for a certain short distance, blue and yellow 
extend farther out, and after this only the achromatic series is 
visible. We are immediately reminded of the way in which the 




Fig. 49. — Campimeter for plotting the distribution of color-sensitivity 
in the retina (modified after one by Carr). M, motor and color-disks 
behind the campimeter screen. This screen and the metal closing the 
aperture can be of any brightness from black to white. R, the head-rest. 
The screen is arranged in the figure to test the nasal part of the right eye or 
the temporal part of the left eye. It can be rotated in order to test the 
other portions of the retina. 

rods and cones are distributed in the retina — in the fovea cones 
only, toward the periphery more and more rods and fewer and 
fewer cones. The further significance of this fact we shall com- 
ment on later in the section on "Theories of Vision." Ferree 
and Rand have probably secured the best experimental control 
of the factors influencing the extent of the color-zones, the most 



258 GENERAL PSYCHOLOGY 

important of these factors being: (1) the size of the color- 
stimulus, (2) the general illumination of the room, (3) the 
brightness of the pre-exposure (i.e., of the object which is used 
to close the aperture in the screen of the campimeter and which 
therefore affects the eye just before the color is exposed), and 
(4) the brightness of the screen surrounding the aperture. One 
can hardly generalize the results without some error. As a 
rule, however, the extent of the color-zones is less with: (a) a 
decrease in the size of the object (area of the screen aperture) ; 
(b) a decrease in general illumination; (c) a pre-exposure 
which is very much brighter or darker than the color tested; 
and (d) a surrounding screen which differs markedly from the 
color-stimulus in brightness. The last two factors may be 
explained by the fact that white added to a color decreases 
its saturation far more rapidly than does an equal addition 
of black, and by the fact that each has a greater effect 
than a gray of the same brightness as the color. A small 
sector of yellow in black can be distinctly seen when rotated 
on a color-wheel while the same amount would remain invisible 
if added to white. This condition is true regardless of the 
method of adding the black or white, whether by actual mix- 
ture on the wheel, by simultaneous contrast (surrounding field) , 
or by the negative after-image (pre-exposure). 

Ordinarily we do not notice that objects in the periphery of 
vision are colorless. This fact is due partly to suggestion on 
the basis of what we know concerning the color of the object, 
partly to frequent eye-movements that reveal the color, and 
partly to the great size of many objects, e.g., walls and houses, 
which actually brings the color above the threshold. 

Color-Blindness. — We have already discussed the fact that 
the normal human eye is color-blind under conditions whereby 
homogeneous light- waves (colors) arouse only achromatic sensa- 
tions. Certain individuals are termed color-blind because they 
are unable under any circumstances to see certain colors. The 



SENSORY PROCESSES 259 

defect may be due to disease or it may be congenital, being 
inherited in the latter case according to Mendel's law. Color- 
blindness may be total. In this case the individual sees all 
objects in blacks, whites, and grays. Usually, however, color- 
blindness is only partial, and the individual is insensitive to 
certain rays only. Those persons more insensitive to the long 
rays than to the short are termed by von Kries protanopes 
(red-blind), while those less sensitive to the short rays than to 
the long are termed deuteranopes (green-blind). Occasionally 
one finds tritanopes, who are blue-blind and who may confuse 
blues and yellows. This condition of color-blindness is a result 
of disease and is very rarely found. 

The detection of the protanopes and deuteranopes is par- 
ticularly important because of the use of red and green lights 
on railroads and steamship lines. Two prominent methods of 
diagnosis are employed. One, the Holmgren wool test, is 
widely known and used for rough examinations. A large num- 
ber of varicolored skeins of wool are placed before the subject 
who is instructed to place all skeins of a given hue into one pile. 
The protanopes ignore the element of red in the skeins and 
class together the reds, oranges, and yellows, and the blues and 
purples. The deuteranopes ignore the green element, and con- 
sequently place a greenish yellow with green, and a blue-green 
with blue. The other method, which yields more accurate data 
concerning the exact nature of the individual's defect, requires 
him to match each of the various hues of the spectrum with a 
combination of two wave-lengths. (In the normal eye this is 
only possible with three wave-lengths.) Figure 50 shows results 
obtained by Koenig. Thus both the red-blind (protanopes) and 
the green-blind (deuteranopes) can match any hue from red 
to orange by merely increasing the intensity of the wave-length 
645 nfjL (red) . From orange on a varying amount of blue 
(460 fxfji) must be added in order to match the hues. The 
abscissa records the wave-lengths of the colors to be matched, 



260 



GENERAL PSYCHOLOGY 



and the ordinate values show the relative amounts of the red 
and blue required. Thus blue-green (500 /jl/jl) is matched by the 
protanope by 5 units of red (645 juju) and 3 units of blue (460 /*/*). 
The deuteranope requires the same amount of blue but, being 
less insensitive to the long wave-lengths than is the protanope, 
only 2 units of red in order to make the match. 



































































X 




































f \ 








14 - 




















j 


T 




4 










12 - 


















JL 








T 










8 - 














m 












1 










6 - 

4 - 
2 - 












/ 


_!__ 






— 1 


1 


• 






J 




1 1\> 



720 700 680 660 640 620 600 580 560 540 520 500 480 460 440 420 400 380 

a B C D E b F G H 

Fig. 50. — Curves showing chromatic matches for the red and green 
blind (from Parsons after Koenig). W 2 and Wi are the curves for red for 
the red-blind and the green-blind, respectively. K is the blue curve for 
both. The curve H need not concern us. The figure is described further 
in the text. 

Twilight Vision. — So far in our account we have considered 
the phenomena of vision only under daylight stimulation. 
Twilight vision, however, must be discussed, that is, vision in 
light of low intensity which is favored by dark-adapted eyes. 
When one passes from a light room to a dark room, one is at 
first unable to see, i.e., one is not at once dark-adapted. Later 
the difficulty clears up, and he becomes particularly sensitive 
to faint lights. The end-organs that become active are the 
rods in the retina — a fact that can be demonstrated on a dark 



SENSORY PROCESSES 261 

night by noting that a faint star becomes brighter if one looks 
just to the side of it. By this method retinal stimulation is 
shifted from the fovea where there are no rods to the adjoining 
rod-supplied regions. A light may be used which is actually 
invisible unless it stimulates the periphery of the eye. 

One of the chief phenomena of twilight vision is the Purkinje 
phenomenon. In daylight vision, i.e., in light of good intensity, 
the yellow is the brightest hue of the spectrum. In twilight 
vision, on the other land, the brightest hue is toward the blue- 
green. This shift in brightness does not occur at the fovea,- 
nor does it occur in totally color-blind individuals. For this 
reason it has been used to a certain extent as a test for color- 
vision in animals below man. It is also of interest to observe 
in connection with the sensitivity to faint light found in twilight 
vision that night birds, e.g., owls, have only rods in their retinae, 
while day birds, e.g., chicks, have only cones. 

Theories of Visual Qualities. — The theories of visual 
qualities are attempts to construct the probable nature of the 
processes going on in the retina which underlie and condition 
the phenomena that we have been describing. The most 
prominent theories are those of Helmholtz and Hering. The 
former, although many times modified, is much less tenable than 
the latter. Helmholtz's theory assumes that the retina contains 
three substances called, after the color-qualities that they con- 
dition, the red, green, and violet substances. Light-waves 
stimulate all of these, but in unequal degrees. When all are 
stimulated in the proper proportion, an achromatic sensation 
results. This theory is at its best in the explanation of color- 
mixture, inasmuch as a proper combination of red, green, and 
blue will match all hues. Positive after-images are regarded 
as due to the inertia of the retinal substances. Thus, a certain 
after-image red is seen because, once the red substance is 
chemically affected by the light, it cannot stop at once when the 
stimulus is removed. Negative after-images are regarded as 



262 GENERAL PSYCHOLOGY 

due to unequal fatigue of the retinal substances. Thus, when 
yellow light affects the eye, the red and green substances which 
condition it are partly used up. Light now can affect only the 
violet substance, giving a blue which is the after-image. The 
theory fails to account for color-blindness, for peripheral vision, 
and for the perception of color at low intensity as gray. Its 
great defect lies, therefore, in the absence of a special mechanism 
for the explanation of the achromatic series. 

This is remedied in the Hering theory as modified by Mueller 
and von Kries. This theory is the most widely accepted one 
today, its chief rival among American psychologists being the 
Ladd-Franklin theory. 1 Hering's theory assumes in the retina 
three substances: black- white, red-green, and blue-yellow. Of 
these the black-white, which is the most sensitive and the most 
widely distributed, is affected by all waves of light and is found 
both in the rods and in the cones. The color-substances, how- 
ever, are found only in the cones and respond only to homo- 
geneous light-waves. Each of the three substances has two 
antagonistic modes of activity underlying the two qualities 
specified in the name (black- white, e.g.). Color-mixture is 
explained on the same principle as in the Helmholtz theory, 
viz., by the stimulation simultaneously or in rapid succession 
of two or more color-substances in the same retinal area. Com- 
plementary color-mixture is explained as follows: If the red 
phase and the green phase of the red-green substance are stimu- 
lated with a certain relative intensity, the two antagonistic 

1 This theory, proposed by Mrs. Ladd-Franklin, lays particular stress 
upon the hypothetical origin of the color-substances. Black-white was the 
first substance to appear in the development of the eye and still dominates 
the periphery of the retina. The blue-yellow substance was the next to 
appear, and is found better developed in the middle color-zone than is red 
or green. The last substance (red-green) developed from the yellow sub- 
stance. The theory makes possible several valuable interpretations in 
qualitative vision, but it is neither widely enough accepted nor of sufficient 
historical merit to justify an extended discussion here. 



SENSORY PROCESSES 263 

processes balance each other and consequently fail to give rise 
to any color-sensation. The light, however, still affects the 
black-white substance, and the result is a gray. The difficulty 
comes in the case of the black-white substance itself. Why 
does not a proper combination of the antagonistic processes 
in this substance result in a cancellation of all gray visual 
quality in place of resulting in a medium gray? To meet this 
objection Mueller has advanced the hypothesis that in addition 
to the gray of the black-white substance in the retina there is a 
"cortical" gray, conditioned by central (cortical) processes, 
which is active and becomes prominent when the black- 
white processes cancel. This hypothesis, however, is too 
much at variance with the current tendencies in sensory 
theories to warrant its acceptance as yet. It is perhaps best 
to regard the black-white substance as unique among retinal 
substances with respect to this particular point. On the Hering 
theory color-blindness is explained as an absence of certain 
color-substances. Peripheral vision is based upon the fact of 
the varying distribution of the visual substances in the retina. 
Twilight vision is a matter of the lower sensitivity of the black- 
white substance found in the rods; thus a light too faint to 
affect the color-substance may still arouse an achromatic sensa- 
tion. Positive after-images represent an inertia of the chemical 
activity, negative after-images being due to the tendency of the 
visual substances to maintain an equilibrium between the 
antagonistic processes. Accordingly, if the red process is 
stimulated, the green is thrown into activity before equilibrium 
is again attained. Simultaneous contrast is inadequately 
explained by all theories, Hering assuming that the activity 
of one process in one part of the retina arouses an activity in 
the antagonistic process in immediately contiguous retinal areas. 
Specific Nervous Energy. — We turn now from the con- 
sideration of individual sense-fields to a brief study of two 
general phenomena of sensory processes referred to as the 



264 GENERAL PSYCHOLOGY 

problem of specific nervous energy and the problem of sensation 
intensities. We shall consider the topics in the order named 
above. Why does the stimulation of the eye give rise to a 
conscious quality different from that conditioned by the ear? 
It cannot be entirely due to the fact that vision is aroused by 
light-waves and sound by air-waves, for both senses become 
active when stimulated by blows on the head and by the electric 
current. In the same manner, one fails to explain the differences 
between other sensory qualities on the basis of differences in 
stimuli because of this relative indifference of the stimuli-pro- 
ducing sensory qualities (thus, blows on the body may produce 
sound, pain, light, and pressure). To explain the phenomenon, 
Johannes Mueller (1834) proposed the hypothesis that each 
nerve has a specific energy which will produce its own quality 
and no other. Later workers have extended the theory to 
include the ascription of different energies to the same sense- 
field in order to account for qualitative differences within a 
single sense. Experimental technique, however, is unable to 
discover differences in nervous impulses. Those from the eye 
are to all intents and purposes exactly like those from the ear, 
and all impulses from each receptor appear identical. Present 
theories, as we have seen in the case of vision and hearing, 
explain the appearance in consciousness of sensory qualities 
in terms of processes going on in the receptors. Inasmuch, 
however, as consciousness only arises from brain activities, 
these differences in sense-organ activities must be carried over 
the nerves and into the brain. Accordingly there must undoubt- 
edly be differences in nervous impulses. Perhaps some time 
in the future it may be possible to detect these differences 
experimentally, but at present it is impossible to get at the 
essential changes even in the sense-organs save by theory. It 
nevertheless seems most plausible to place the essential physical 
conditions of sensory qualities in the receptors partly because 
of their highly complicated structure (which we assume must 



SENSORY PROCESSES 265 

have a function) and partly because it is known that if the 
receptor is lost early in life the individual loses all imagery 
from this field. Visual imagery, for example, is absent in an 
individual whose sight is lost early in childhood. It would 
seem, therefore, that the specific physical process is initially 
dependent upon sense-organ activity, and then becomes supple- 
mented by changes in the cortex. After this supplementation 
occurs, the loss of the sense-organ does not deprive the individual 
of all states of consciousness connected with that sensory field; 
he still retains images and memories. The question of specific 
nervous energy is the problem of the exact neural equivalent 
of sensory qualities. Even more, it is in the, last analysis a 
concrete formulation of the question of the relation of mind and 
body, i.e., of what goes on in the body when a given quality 
o'f consciousness exists. 

Sensation Intensities, Weber's Law. — We have been con- 
cerned up to this point largely with the important problem of 
sensory qualities. Sensation intensities have only been men- 
tioned in so far as they affect qualities, e.g., in the question of 
twilight vision, but the topic of intensities is important in itself. 
As a matter of historical fact Ernst Weber in 1854 started the 
science of psychology with investigations of this question. The 
form in which the earlier workers put the problem is still with us: 
What is the relation between the intensity of the stimulus and 
the intensity of the sensation, and how does the latter change 
as the former increases? Weber's original work was upon the 
relation between the increase in intensity of pressure from lifted 
weights and the increase in the magnitude of the weights them- 
selves. He found that the stimulus must be increased by a 
certain constant ratio in order that the sensation might be just 
noticeably more intense each time. With lifted weights Weber 
determined the ratio as 1/40. This means that no addition 
to a weight of 40 ounces will be noticed unless it at least equals 
1 ounce, while to 40 pounds 1 pound must be added. The 



266 GENERAL PSYCHOLOGY 

law so stated has been found true for all the middle range of 
sensation intensities belonging to the following classes: light, 
noise, tone, pressure, kinaesthesis, and smell. The ratio in 
light is i/ioo; in tone, 1/8; in noise, 1/3; in pressure, 1/30; 
and in smell, about 1/3. Each of these ratios is an average 
based upon a large number of observations and admits of con- 
siderable variation. Upon these experimental results we may 
formulate the fact that a slight difference in a small object is as 
readily noticed as a great difference is in a large object, the 
problem involved being that of the differential threshold for 
intensity. For studies of behavior, as opposed to studies of 
conscious processes, the phenomenon of Weber's law is important 
in pointing out the least differences between stimulus intensities 
that can afford a basis for two different responses. In the case 
of a rat, for example, if a light x is chosen on the basis of its 
greater intensity when compared with y, how much must the 
intensity of y be increased before the animal fails to make the 
distinction between x and y ? 

Following Weber, Fechner performed many similar experi- 
ments in other sense-fields, and finally formulated the law in 
mathematical terms that need not concern us here. The theo- 
retical problem growing out of the phenomena of Weber's law 
involves the explanation of the loss in energy between stimulus 
and sensation. Fechner regarded the relationship as a mathe- 
matical one showing the ultimate relationship of mind and 
body. For this reason he termed the topic psycho physics. 
Ebbinghaus and Mueller interpret the loss of energy as an 
instance of increased resistance of the nervous system to the 
transmission of impulses resulting from increased intensity of 
stimulation. Ebbinghaus would place the major portion of 
this resistance in the cortex. The fact of prime importance 
for us to remember, however, is that the awareness of sensation 
intensities is a relative matter limited in each sensory field by 
a definite ratio. 



SENSORY PROCESSES 267 

The Awareness of Space. — Passing from the study of sensa- 
tion qualities and intensities, we come to a consideration of two 
additional attributes of sensation, location and extension, the 
data on which constitute the psychology of space. The topic 
is one of great importance and of voluminous literature. We 
can only indicate here a few of the most fundamental problems 
and the general trend of the data bearing upon them. Common 
sense and some philosophy lead one to believe that the world 
outside of consciousness exists in spatial form. We have a 
very complex and highly elaborated conception of space which 
we term geometrical or mathematical. This we assume to be a 
fair copy of physical space. In this mathematical space, for 
instance, parallel lines never meet and things equal to the same 
thing are equal to each other. However, these axioms do not 
apply to space as we are immediately aware of it. When we 
compare this fact with the teaching of mathematics, we term the 
psychological fact an illusion, but it still remains a fact of 
experience. If a compass with points one inch apart is moved 
from cheek to cheek with the points on each side of the mouth, 
the lines diverge as the points pass the lips. Not only the 
first but also the second axiom mentioned above is inapplicable 
to conscious space due to the differential threshold. We may 
illustrate in this manner: Light A (100 c.p.) looks equal to 
light B (100.5 c.p.). Light B looks equal to C (101 c.p.); 
but A looks less than C, not equal to it, because the differential 
threshold for light intensity (1/100) has been passed. 

The space of immediate awareness owes its peculiarities 
to the limitations in the structure and function of the receptors. 
These, as we saw earlier in our classification of the senses, adjust 
the organism to the space-characteristics of the stimuli as well 
as to the variations in vibration-rate and amplitude, or to 
quality and intensity. The space that is built up from these 
sensory data is grounded upon the so-called space-senses, vision 
and touch, which are adapted to stimuli that do not bend— 



268 GENERAL PSYCHOLOGY 

vision as a distance receptor and touch as a contact receptor. 
This condition, coupled with the fact that each receptor group 
has an extended receiving surface (retina and skin), is at the basis 
of their fundamental significance for space-perception. The 
cochlear canal and the olfactory membrane are also extended in 
space; but the stimuli which affect them bend and consequently 
are not adapted to the space-characteristics of objects. All sensa- 
tions, as well as all states of consciousness in general, are located 
more or less definitely within the visual- tactual space-world. 

Only vision and touch experiences, however, are intrinsically 
extended. The extension present in other sensations is an 
extension borrowed from these two. Low-pitched tones seem 
larger, more voluminous, more extended, than higher tones. It 
is probable, however, that this is due to an association estab- 
lished between certain pitches and the sizes of the object pro- 
ducing them. The fall of a tree makes a more voluminous sound 
in this sense than the fall of a cane. In addition many volumi- 
nous sounds actually jar the body, aiding in the impression of 
bigness through added associations. 

The chief topics in the study of space-characteristics are 
as follows: Under extension come the three problems of size, 
form, and distance in the third dimension. In addition we 
have the question of the accuracy of location and the problems 
of movement, or change of location. In each case a detailed 
consideration must include a study of the development of the 
various abilities during the individual's lifetime, a study of the 
nature of the sense-organs involved, and a study of the varia- 
tions in the various abilities at different parts of the body and 
under various conditions of fatigue, disease, etc. In the account 
that follows we shall comment upon one or two topics in each 
of the three fields most thoroughly studied — touch, hearing, and 
vision. 

Tactual Space. — One of the fundamental problems in tactual 
space is that of the localization of a touch-sensation (i) with 



SENSORY PROCESSES 269 

reference to another touch and (2) with reference to a visual 
sensation. The first phase of the question may be stated as 
follows: If a given point on an individual's hand is touched 
while he is blindfolded, how accurately can he then touch the 
same spot; or how far apart must two compass points be before 
they are sensed as two? The second phase brings out much 
the same phenomena and is tested by having the subject indicate 
on a model of the arm the location touched. The whole ques- 
tion may be styled the problem of the two-point threshold. 




Fig. 51. — An aesthesiometer 

When the compass points are used, the apparatus is an aesthesi- 
ometer (Fig. 51), and the two points may be applied simul- 
taneously. The procedure consists in applying the points quite 
widely separated at first and then closer and closer together 
until the subject gives the judgment "one." Then the experi- 
menter starts with a separation a little less than this and 
gradually increases the distance of the pointers until the subject 
responds with "two." The average of a large number of 
descending and ascending judgments is termed the two-point 
threshold. Care must be taken that the compass tips are poor 
conductors of heat (hard rubber is usually used) or temperature- 
sensations serve to disturb the test. As the compass points 



270 GENERAL PSYCHOLOGY 

approach each other in the descending series, the distinct aware- 
ness of "two-ness" finally gives place to a dumb-bell-shaped 
contact which, as the points are further approximated, gradu- 
ally changes to the awareness of a point. Practice enables the 
individual to interpret these changes and consequently to 
decrease his threshold — i.e., to increase his apparent sensitivity 
to location differences. 

Weber found that the threshold was least on the tip of the 
tongue and greatest in the middle of the back and on the upper 
arm and leg. A few of his measurements are here given: 

Tip of tongue i mm. 

Red of lips 5 mm. 

Cheek 11 mm. 

Back of first phalanx of finger 16 mm. 

Back of hand 31 mm. 

Middle of back 68 mm. 

He also found that localization was more accurate on the arms and 
legs in a transverse than in a longitudinal direction. Further- 
more with successive stimulation the threshold is lower. Judd 
found that each pressure-spot could be distinguished unless the 
spots were so close that individual stimulation was impossible* 

In explanation of localization Lotze proposed that each 
pressure be regarded as having a peculiar quale called its local 
sign by virtue of which it could be assigned to a distinct part 
of the body. The two-point threshold would therefore be the 
limit of "difference between local signs. Bernstein and von Frey 
suggest that each stimulation produces an irradiation in the 
skin 1 and that where the two irradiations overlap greatly a 
sensation of "one-ness" results. The facts are not yet available 
which will permit a decision between the theories. 

Auditory Space. — Here again, in order to illustrate the topic, 
we are to deal with the question of accuracy of localization. 

1 Bernstein thought of it as in the nervous system. 



SENSORY PROCESSES 



271 



Our discussion may be brief. The apparatus usually employed 
is termed a sound-cage and enables one to present a sound in 




Fig. 52. — A sound-cage. The upright bar which carries an iron arc 
with a telephone receiver on it can be rotated about the subject seated on 
the stool. The telephone receiver can be varied in location anywhere in 
a sphere surrounding the subject's head. 

any direction from the subject who is seated within it (see 
Fig. 52). Localization is most accurate between the region 
opposite each ear and the median plane of the body, but when 



272 GENERAL PSYCHOLOGY 

a sound is given in this median plane it is difficult for the sub- 
ject to say whether it comes from in front or from behind. The 
sound-waves in this case stimulate the two ears with practically 
equal intensities. In the part of space lying immediately about 
the axis running through the two ears sounds are accurately 
localized as being on one side or the other of the body, but 
changes must be of several degrees before a change in the 
localization of the sound is observed. 

As we have just suggested, the relative intensity of the 
sound to the two ears is a fundamental fact in the appreciation 
of sound direction. Angell and Fite have shown, furthermore, 
that tonal complexity is an aid in sound localization, for pure 
tones cannot be accurately located in space. When the air- 
waves conditioning a complex tone stimulate the two ears, the 
more distant ear fails to receive many of the high overtones due 
to the sound-shadow produced by the head. Such changes in 
the timbre of the klang facilitate accurate space-discrimination. 
Other factors have also been proposed as aids in localization, 
but they do not merit discussion here. 

Visual Space. — Not only does vision give the most accurate 
information concerning the lateral extension of objects, but 
it is also the only distance-sense that gives more than a rough 
approximation of distance or extension in the third dimension. 
It is of peculiar importance to the individual in adjusting him- 
self to his environment to secure information upon this point. 
A part of the awareness of depth is truly visual, i.e., is 
dependent upon peculiarities of retinal stimulation. Much, 
however, is based upon kinaesthetic nervous impulses coming 
from the ciliary muscle and from the six extrinsic muscles of the 
eye, that is, from impulses aroused by accommodation and 
convergence. 

The chief visual characteristic which determines distance 
is that of binocular disparity. If one fixates an object with both 
eyes, it can be readily demonstrated by closing first one eye 



SENSORY PROCESSES 273 

and then the other that the two eyes are stimulated by different 
aspects of the stimulus. The fusion of these two disparate 
retinal stimulations gives the perception of depth, or stereoscopic 
vision. It is this fact that makes objects appear solid and not 
flat. Whenever the eyes fixate a given point, there is a series 
of points in space that are focused accurately on the retina and 
that are therefore seen clearly. These points constitute the 
horopter. When the eyes fixate an object near by, the horopter 
is essentially a circle passing through the two eyes, the fixation 
point, and a line perpendicular to the circle through the fixation 
point. All points not included in this horopter are seen doubled. 
Those that lie nearer than the fixation point are reversed so that 
the right eye sees the left point and vice versa. Those lying 
farther than the fixation point are not reversed. The points 
included in the horopter stimulate corresponding points on the 
two retinas, while all other points fall upon non-corresponding 
points. These variations in retinal stimulations, however, 
come to consciousness only upon reflective analysis of the type 
we have used here, for the neural processes ordinarily fuse below 
the threshold of consciousness. We are aware of them, then, 
only as the awareness of solidity and depth. 

The nervous connections that condition the fusion of 
disparate retinal stimulations are quite probably inherited. 
There are other visual cues in depth-perception, however, that 
are acquired by experience. The interposition of one object 
between the eye and another object indicates that the latter is 
farther away. Hazy objects are also usually judged as distant. 
The sizes of known objects afford other cues, e.g., an object that 
is recognized as a man, if very small, is judged far away. The 
estimation of distance at sea is rendered difficult largely because 
of the absence of familiar objects upon which to base judgment. 

The two remaining important cues used in depth-perception 
are convergence and accommodation. When a near object is 
fixated, the two eyes converge more than for the observation 



274 



GENERAL PSYCHOLOGY 



of a more distant point. This variable intensity of muscular 
contraction can therefore serve as a cue for nearness and remote- 
ness. It functions primarily with a binocular perception of 
depth. In accommodation the sensory impulses come from the 
ciliary muscle in which increased contractions occur with 
increased nearness of the object. The mechanism of change 
in the shape of the lens is shown in Fig. 53. The contractions 
loosen the suspensory ligament holding the lens, and the latter 
bulges out in thicker form by virtue of its own elasticity (Helm- 
holtz). It is practically impossible to separate the two factors 
and assign one (convergence) to binocular vision and the other 




Fig. 53. — Variation in shape of lens during accommodation; s, sus- 
pensory ligament; c, ciliary muscle. 



(accommodation) to monocular vision. Even with one eye 
closed, that eye continues to move in harmony with the open 
one and so continues to produce the normal convergence 
impulses. It is pretty generally agreed that the kinaesthetic 
data contributed from these two processes, although they are 
of value, nevertheless do not make accurate judgments possible. 
The judgments of depth made in monocular vision are based 
largely upon the secondary retinal criteria stated above. 

Functions of Sensory Processes. — It is obviously difficult 
to generalize the functions of the many sensory processes that 
have been studied in the preceding chapters. As usual the 
question must be approached from the standpoint of conscious- 



SENSORY PROCESSES 275 

ness as well as from that of behavior. From the former_angle 
the chief function of sensation lies in constituting the funda- 
mental stuff of consciousness, a condition that was made clear 
in our earlier study of emotion and affection. This statement 
stresses sensory qualities. Intensities, meanings, locations, so 
far as they are connected with images, however, may be like- 
wise traced back to original sensory attributes. The only 
exception is the possible one of affective qualities, for most psy- 
chologists believe that these deserve a place with sensations as 
the original stuff of consciousness. In the following accounts 
of imagination, memory, and thought, the fundamental place 
of sensory material will be further appreciated. From the 
behavior side we must speak of the function of receptors and 
sensory impulses. Receptors function as the most sensitive 
receiving structures in the body. They are the immediate 
go-between for the environmental changes and the organic 
responses. Their detailed function has been discussed in con- 
nection with "Attention" (p. 115) and with the " Classification 
of Sensations" (pp. 221 ff.). Sensory nervous impulses have 
their function in arousing the activity in the effectors which con- 
stitutes the behavior of the organism. Overt behavior may 
be long delayed and may even never appear as a recognized 
response to the earlier sense-organ stimulation. I may see a 
painting or hear a symphony and never have my conduct 
modified in such a fashion that the modification can be traced 
back to the influence of these events. Nevertheless, immediate 
bodily responses have occurred at the time of the stimulation, 
perhaps in the form of emotional disturbances or perhaps only 
in the form of the motor accompaniments of attention. 

One need not attempt to decide which functions are the 
more important, those from the standpoint of behavior or those 
from the point of view of consciousness. The problem must be 
approached from both angles if a true perspective is to be 
secured. 



276 GENERAL PSYCHOLOGY 

REFERENCES 

Angell, J. R. Psychology. Fourth edition. New York: 1908. 
Baird, J. W. "The Color Sensitivity of the Peripheral Retina," 

Carnegie Institution of Washington, Pub. No. 29, 1905. 
Bingham, W. V. "Studies in Melody," Psych. Rev. Mon., XII 

(1909), No. 50. 
Calkins, M. W. A First Book in Psychology, pp. 301-10. Fourth 

edition. New York: 19 14. 
Cunningham's Text-book of Anatomy. Fourth edition. New York : 

Hardesty, I. "On the Nature of the Tectorial Membrane and Its 
Probable Role in the Anatomy of Hearing," Amer. Jour Anat., 
VIII (1908), 109-79. 

— . "A Model to Illustrate the Probable Action of the Tectorial 

Membrane," Amer. Jour. Anat., XVIII (1915), 471-514. 

Helmholtz, H. von. Sensations of Tone. Trans, by Ellis. London: 
1885. 

Ladd, G. T., and Wood worth, R. S. Elements of Physiological 
Psychology. New York: 191 1. 

Le Conte, J. L. Sight. London: 1883. 

Moore, H. T. "Genetic Aspect of Consonance and Dissonance," 
Psych. Rev. Mon., XVII (1914), No. 73. 

Parsons, J. H. An Introduction to the Study of Color Vision. Cam- 
bridge: 1915. 

Peterson, J. "Combination Tones and Other Related Auditory 
Phenomena," Psych. Rev. Mon., IX (1908), No. 39. 

Pierce, A. H. Studies in Auditory and Visual Space Perception. 
New York: 1901. 

Rand, Gertrude. "The Factors That Influence the Sensitivity of 
the Retina to Color," Psych. Rev. Mon., XV (1913), No. 62. 

Shambaugh, G. E. "A Restudy of the Minute Anatomy of Struc- 
tures in the Cochlea with Conclusions Bearing on the Solution 
of the Problem of Tone Perception," Amer. Jour. Anat., VII 
(1907), 245-58. 

Titchener, E. B. Text-book of Psychology. New York: 1910. 

Watt, Henry J. The Psychology of Sound. Cambridge: 191 7. 



CHAPTER VIII 
IMAGINATION AND THE SEQUENCE OF EXPERIENCES 

I. IMAGINATION 

The Image and Sensation. — If an air- wave of 256 vibrations 
per second stimulates my ear and finally arouses a nervous 
activity in the temporal lobe of the brain, the resulting state of 
consciousness is a sensation — in this case an auditory sensation. 
With another stimulus and another receptor the sensation 
might have been one of pressure, taste, or vision. We have 
defined these conscious states as the awareness of objects as 
present to sense. If, however, I am aware of sound, taste, or 
visual objects when the corresponding receptors are not stimu- 
lated in such a way as to arouse these states of consciousness, 
I am experiencing an image. In this case the nervous activity 
in the temporal lobe, if the image is an auditory one, is aroused, 
not directly from some sense-organ, but from some other area 
in the cortex. This is called central arousal. Sensations are 
peripherally aroused, i.e., the nervous impulses which condition 
them reach the cortical center without first passing through 
other cortical centers. 

By an image is meant the consciousness of an object as not 
present to sense. With sensory processes we found a belief in, 
or acceptance of, the physical presence of the object. In 
imaginal processes there is belief in the physical absence of the 
object. The lack of this feeling of reality with images is to be 
accounted for on the basis of the following differences between 
them and sensations: (1) Images are usually less intense than 
sensations. (2) They are also usually less stable, i.e., they 
fluctuate and come and go in a way that sensations do not 
unless they are very near the limen of sensitivity. (3) Images 

277 



278 GENERAL PSYCHOLOGY 

usually contain less detail. If the sensation is of red, the image 
will also be red — and may be of the same shade — but the outline 
is likely to be less clear. If the sensory process is a perception 
of a chair, the image again will not usually contain as much of 
the detail as can be seen or felt. A part of this deficiency in 
detail in imagery is probably due to the lack of stability which 
we mentioned above. (4) Imaginal objects cannot be verified 
by the other senses. If I perceive an object visually, I am 
usually able to go over and touch it or lift it, thus convincing 
myself that the object is actually present. When, however, I 
have a visual image of the object, it is impossible to touch, lift, 
or hear it. Because of these four differences, we find but few 
instances in which we have difficulty in judging whether we 
are experiencing a sensation or an image. These are usually 
cases of sensations near the threshold of sensitivity. 

Images, like sensations, have all the general attributes of 
consciousness in varying degree. The belief, that is peculiar 
to the image, in the physical absence of the object is a meaning 
ascribed to it. It may also have other meanings limited as to 
kind only by the nature of one's past experience. Thus a 
certain round image may mean the moon, an apple, a golf ball, 
or anything else with which it may have been associated in the 
past. In respect to intensity, however, it has sometimes been 
claimed that images lack this attribute (Ebbinghaus) and that 
the auditory image of a peal of thunder is no more intense than 
the auditory image of a whisper. Images that are aroused 
shortly after the original sensory processes do differ in intensity, 
but, as they increase in age, it is true that differences in intensity 
are largely overcome until all images may become alike in this 
respect. Concerning the other general attributes of conscious- 
ness possessed by images, i.e., duration, clearness, location, etc., 
no particular comments are required. It is important here 
merely to emphasize the fact that images are not necessarily 
localized within the head. My image, for example, of Camp 



SEQUENCE OF EXPERIENCES 279 

Lee, Virginia, lies in front of me and contains barrack buildings 
of a size to lead me to say that they were one-fourth of a mile 
away. It is the low intensity and poor stability of the image 
which leads the popular observer to overlook the fact of the 
frequent external localization of images. 

The Neural Basis of Imagery. — We have already com- 
mented upon the fact that images are centrally aroused while 
sensations are peripherally aroused. That is one very impor- 
tant characteristic of the • neural action underlying imagery. 
Attention must now be called to the fact that the neural basis 
of image quality is undoubtedly the same as that of its cor- 
responding sensation. There is no good reason for saying, 
granted that cortical activity X is the basis of the quality red 
set up by stimulation of the eye, i.e., in sensation, that any 
other cortical activity Y is necessary when the quality red is in 
consciousness as an image. There must usually be a difference 
in the nervous processes conditioning intensity, duration, and 
stability, because these characteristics are different in sensa- 
tion and imagery. The chief neural difference, aside from that 
of central versus peripheral arousal, comes in the associated 
neural processes that give meaning to the experiences. In 
sensation the meaning is "present to sense"; in imagination 
the meaning is "not present to sense." 

Image-Types. — Not all sensory processes, let it be said, are 
equally susceptible to central arousal. It is difficult to secure 
images of taste, smell, organic, and kinaesthetic experiences. 
Visual and auditory images are the most common, with cutane- 
ous and kinaesthetic ones probably holding a middle place. 
The pioneer study of this question of the distribution of mental 
imagery was made by Francis Galton ( 1 883) . Galton submitted 
a questionnaire to his scientific friends which requested them 
to describe in detail the image they retained of their morning's 
breakfast table in regard to color, illumination, definiteness of 
outline, etc. Much individual variation was found, many even 



280 GENERAL PSYCHOLOGY 

denying that they possessed visual imagery. Later tests were 
made upon imagery from the other senses and equally variable 
results were secured. 

Images, as the above paragraph suggests, are usually classi- 
fied on the basis of the sense-organ involved in the original 
sensation. Charcot has called our attention to the need of 
recognizing verbal imagery in addition to concrete imagery, i.e., 
images of words which may in their turn belong to any of the 
sensory classes. Thus one may have the image of a cow in the 
form of a printed word or as a word spoken. With individuals 
whose thinking concerns highly elaborated and abstract material 
(as is the case with most professional callings) , the tendency is 
for verbal imagery to replace concrete imagery. This tendency 
is intelligible when it is recalled what a large place language 
plays in man's adjustments to his surroundings. 

Working upon this preliminary basis, psychologists, notably 
Segal, Betts, Mabel Fernald, and James R. Angell, have can- 
vassed very thoroughly the possibility of assigning individuals 
to certain image-types and of terming them visualizers, audiles, 
motiles (users of kinaesthetic images), and other types. In 
judging whether a given individual belongs to one class as 
opposed to another, account must be taken of the relative 
frequency, intensity, and accuracy of the two forms of imagery. 
Stated briefly, the result of the experimentation has been that 
nothing approximating rigid image-types exists, for centrally 
aroused consciousness is too profuse, complex, and plastic to be 
contained in such molds. Individuals may use a certain form 
of imagery at one time for a problem and another form at a 
later time for the same problem when it recurs. This means 
that if a problem is given a subject, he will report from time to 
time different kinds of imagery used in its solution. This 
method of studying image-type is termed subjective. Various 
objective methods have been proposed which seek to determine 
the nature of the subject's imagery in terms of his time- and 



SEQUENCE OF EXPERIENCES 281 

accuracy-record in the solution of memory-problems. One 
such test consists in comparing an individual's ability to 
memorize materials belonging to vision, audition, etc.; where- 
upon he is assigned to the image-type that corresponds with 
the sensory material in whose learning he excelled. These 
methods are unreliable save as they are checked up by the sub- 
ject's own observation, for no objective methods can be trusted 
to show the presence and kind of consciousness. 

Productive and Reproductive Images. — -Descartes and 
Locke long ago made clear that no qualities exist in imaginal 
form which have not previously existed as sensations; that is, 
to use familiar words, sensation is the fundamental source of 
all knowledge and is one at least of the mental elements. Two 
forms of imaginal reinstatement of past experiences are recog- 
nized — reproductive and productive imagery. By the former 
term we mean imagery that duplicates the earlier experience. 
I see a house, or hear a melody, and later recall these experi- 
ences in imaginal form unmodified. This recall is closely 
related to memory, as we shall see later, and needs only an 
accompanying recognition of the experience to make it a state 
of memory-consciousness. Such imagery has the merits and 
limitations that always pertain to the literal; however, most 
imagery undoubtedly is of this type. Account, however, must 
be taken of many images that appear to be new and that 
resemble hardly at all any objects that one may have seen or 
heard. The musician has in mind an image of a new combina- 
tion of notes which he puts into audible form. The scientist 
has in mind the image of a new process, a new method, or a new 
machine. He can then proceed to construct an object similar 
to his image, but prior to this there has been no sensory experi- 
ence of such objects. These are cases of creative or productive 
imagery. In most cases these new images can be shown to be 
combinations of elements that have been experienced before. 
The first image of a bow and arrow, e.g., combined in a novel 



282 GENERAL PSYCHOLOGY 

• way flexible wood, taut string, and slender projectile, with each 
of which primitive man was already acquainted. The strange 
creations of myth and current fancy — dragons, centaurs, sea- 
serpents — only combine in a novel way sensory experiences that 
are already familiar. The problem is probably correctly 
answered in this manner, but it could not, however, be so sum- 
marily dismissed if a comprehensive discussion were to be given. 
No less authorities than James and Bergson have championed 
the view that no conscious process ever returns as the same 
thing and that the world is essentially novel from moment to 
moment of time. These more speculative, but not therefore less 
valuable, questions must, however, be left for philosophy. 
Genius will always detect relationships and project ideals that 
elude the lesser man and accordingly seem to be essentially 

'novel and creative, however much scientific analysis may show 
them to be but old and reproductive. 

The Function of Images. — The functions that we shall 
ascribe to images are not peculiar to them, but are shared in 
common with those sensations that enter into sequences con- 
trolled by the organism (see p. 285). Images free the organism 
from a dependence upon present sensory stimulation. 1 By 
virtue of the possession of images I can react to objects which 
are not physically present — I can plan a house, sell stock, or 
re-experience an emotion of joy. With images I can build up 
a conception of the universe far surpassing what I can see, hear, 
and touch. The imaginary, however, is not the illusory and 
the unreal. Honor, virtue, character, and all ideals are things 
never present to sense; they are creations of imagination, but 
they are not unreal. Because of their central arousal they are 
usually less compelling than sensory stimulations. It becomes, 
therefore, more difficult to secure a reaction to a moral ideal 
(complex of images) than to the pangs of hunger, for example, 

1 We speak of this as a function of images merely for convenience. It 
is the underlying nervous activity that has the function here outlined. 



SEQUENCE OF EXPERIENCES 283 

but it is done. The Stoic and Epicurean philosophical systems 
are historically great instances where man has fallen back for 
consolation upon imaginal worlds when the world of sensory 
stimulations has broken down and become disorganized. 
Religion is a perennial refuge of this type. 

The great freedom from dependence upon present sensory 
stimulation conferred by the possession of imagery is one great 
difference between man and other animals. He alone possesses 
in any marked degree the ability to respond to an absent series 
of stimuli. This is conspicuously shown in a comparison of 
self-preservation in man and other animals. An animal fights 
to keep its body intact, to ward off sensory pains, and to preserve 
sensory pleasures. Man fights to preserve a system of values. 
He does not fight for life, but for life of a certain kind. Life 
without honor is not worth preserving. 1 

In the gates of Death rejoice, 

We see and hold the good, 
Bear witness earth, we have made our choice, 

For freedom's brotherhood. 

Then praise the Lord, Most High, 

Whose strength hath saved us whole, 

Who bade us choose that the flesh should die, 
And not the living soul. 

As a corollary to the foregoing function of images is the fact 
that images enable the organism to adjust itself to the temporal 
order of natural events. One can recall the past and anticipate 
the future. In every instance, however, the conscious state is a 
present conscious state, although it may have a backward or a 

1 The situation can be stated more behavioristically and, as far as 
animals below man are concerned, more accurately in terms of nervous 
processes. The animal does not have the foregoing purpose in conscious- 
ness, but his nervous system in functioning secures that purpose. The 
nervous processes here are initiated in the sense-organ by present stimuli. 



284 GENERAL PSYCHOLOGY 

forward reference. A conscious state is said to have a back- 
ward reference when it is referred to past moments of time. 
This usually takes the form of recognition, a topic which we shall 
discuss in the chapter on "Memory." In cases of forward 
reference, the individual constructs the probable nature of 
future happenings upon the basis of past experience. It is 
probable that such a combination of past experiences means a 
future event by virtue of the expectant muscular attitude that 
the subject assumes while conscious of the combination. 

II. THE SEQUENCE OF EXPERIENCES 

The Sequence of Images and Sensations. — So far we have 
discussed only the individual image, its type, and function. 
One of the^ striking things about imagery, however, is the fact 
that image succeeds image in a more or less orderly manner. 
The image of the word "war" appears and suggests "Belgium"; 
that suggests the "entry of America into the war"; and so the 
train of images proceeds. This sequence is within the control 
of the individual to the extent that the images desired can 
usually be recalled. For the purpose of comparison our discus- 
sion of sensation needs to be amplified at this point. In sensa- 
tions, which are aroused as we know by present stimuli affecting 
the receptors, there is also a sequence, or succession. Often 
this fact is due to a sequence of stimuli that lie outside of the 
organism's control; thus I pass along a certain avenue, and 
house after house, tree after tree, appears in consciousness. 
The succession of these perceptions is to be explained on the 
basis of a succession of stimuli to the eye. Inasmuch as the 
ether-waves constituting these stimuli are beyond my power to 
produce, if I desire the foregoing sequence of perceptions I 
must place myself before the stimuli. My control consists 
alone in my ability to do this. The sequence of images, how- 
ever, is quite different, for I may secure a succession of them no 
matter where I may be, independent of my power to re-view 



SEQUENCE OF EXPERIENCES 285 

the objects. It is possible to have such a sequence of sensations 
or perceptions also, but rarely if ever in the case of vision. My 
walking or writing proceeds automatically and spontaneously, 
bringing into consciousness a sequence of kinaesthetic and 
cutaneous sensations; or I may swing my arms voluntarily with 
the same result. This case, it will be seen, is essentially of a 
kind with a sequence of images in that it may occur wherever 
I am. Auditory sensations and perceptions fall in a class with 
kinaesthetic processes, i.e., they can be controlled in a manner 
impossible with light. The muscular contractions of the voice- 
mechanism produce not only kinaesthetic sensations, but they 
also set the air in vibration and arouse, consequently, auditory 
sensations which may succeed each other in the form of cries, 
speech, song, etc. Over this sequence I possess a great control 
entirely out of the question in vision where light is the stimulus, 
for I carry around with me the capacity to secure this train of 
auditory sensations just as I do the capacity to secure a train 
of images. In a similar manner I may experience emotions 
and bodily thrills regardless of the absence of the original 
stimulus. Although kinaesthesis and sound are the most 
important instances of sensation sequence within the control 
of man, all of the sensory processes save vision share to some 
extent in the phenomenon. With certain animals, however, 
who carry light-producing organs, even visual stimulations are 
within the organism's direct control. 

The Laws of Association. — The sequence of all these con- 
scious processes — sensations, images, or emotions — is funda- 
mentally determined by the factors discussed in the chapter on 
"Attention" under the title "Factors Conditioning Attention." 
One group of these determining conditions consists of the laws 
of association, concerning which it devolves upon us now to 
secure a thorough understanding. They were first formulated 
by Aristotle and came into prominence in modern times with 
David Hume, David Hartley, and James Mill. The primary 



286 GENERAL PSYCHOLOGY 

law of association is the law of contiguity: If any two states of 
consciousness are experienced together in space and time and if 
later one of them reappears, the other tends to follow. If I see a 
ball and a bat simultaneously (together in space) and if later I 
see the ball or have an image of it, I tend to think of the bat at 
once. If I think of it visually, the re-experiencing of it is in the 
form of an image. If I hear the words ball and bat in immediate 
succession (contiguity in time) and later have either an auditory 
perception or image of the word "ball," I tend to experience 
either an auditory perception or an auditory image of the bat. 
The second term of the association may be peripherally initiated 
in cases where, as we have seen above, the stimulus is within 
the organism's control. This is true in varying degree of all 
conscious processes save vision, being clearly the case with 
emotions and affective processes. If I see a savage dog and 
experience an emotion of fear, later when I see the dog or even 
imagine him I am certain in many cases to re-experience the 
emotion of fear, not in faint imaginal form but as an actually 
present bodily resonance. If I see a certain type of object it 
arouses horror or disgust or mere unpleasantness, and each of 
these emotional and affective conscious processes may be 
re-aroused bodily by an image of the original object. As we 
have pointed out in the preceding section, the majority of these 
sequences of peripherally initiated states of consciousness are 
kinaesthetic, auditory, or emotional in character. Psy- 
chologists since Aristotle have stated that the second term of 
an association must be an image (centrally aroused process); 
but this position we can clearly see is untenable, for the second 
term may be any conscious process whose stimulus is within 
the organism's control. 

The Neural Basis of Association. — The principle under- 
lying association is that of habit-formation, or. the setting of 
synaptic connections in the nervous system. Instincts, for 
example, are cases of inherited associations of reflex arcs, and 



SEQUENCE OF EXPERIENCES 287 

they can be modified during the life of the individual by further 
acquired associations. These later modifications are examples 
of the conditioned reflex discussed on page 16. Although the 
law of association has its historic place as a law of consciousness 
which Hume has likened to the law of gravity in the natural 
world, association cannot be regarded as a force that binds 
mental states together. These latter follow each other in a 
definite way because neural processes follow each other in 
a certain way and not because they are bound together by 
mental ties. 

If we were to diagram the probable neural basis of a typical 
associated series of conscious states, the result would be similar 
to that indicated in Fig. 32. When I see an object, secure 
kinaesthetic sensations of trembling, and experience contact 
sensations from having touched the object, the nervous impulses 
shuttle back and forth between the brain and the periphery of 
the body. They are not confined to the brain itself. From 
the standpoint of the nervous system an association is a connec- 
tion between centers such that when one is active the nervous 
impulses tend most readily to arouse activity in the other. 

Secondary Laws of Association. — Secondary laws of asso- 
ciation have been formulated to supplement the primary law 
of contiguity and to account for the selective action of asso- 
ciation. The law of contiguity explains why some conscious 
states follow others, but it does not account for the fact that a 
particular conscious state and not some other appears. Both 
fire and classwork, for example, are associated in my experience 
with whistles. Why do I at one time think of fire when I hear 
a whistle, and at another think of classwork? It is to explain 
this type of case that the secondary laws have been formulated. 

These secondary laws of association are frequency, recency, 
vividness, primacy, emotional congruity, similarity, and cause and 
effect. Each of these points out some condition by virtue of 
which X follows Y, although experiences A, B, C, and D have 



288 GENERAL PSYCHOLOGY 

also been associated with Y in the past. When I hear the 
word "war" I may think or speak the word "Belgium" by reason 
of the fact that the two have been frequently and vividly con- 
joined in consciousness, or because Belgium was the first thing 
(primacy) connected with the war. After the word "Belgium" 
comes "deportation" by virtue of the recency of the association. 
"Deportation" is followed in consciousness by the word "slave" 
(cause and effect), and "slave" at once suggests "American 
slaves" by similarity. All of these associated terms have the 
same depressing emotional tone, i.e., they are emotionally 
congruous. The reader will do well to trace out other associated 
trains of conscious states in order to convince himself of the 
importance of the laws just stated. 

We should be clear in connection with these secondary laws, 
as we were with the primary law, that we are not dealing with 
psychic (mental) forces. The secondary laws designate, in the 
first place, conditions that favor the continued re-excitation 
of nervous processes. If a nervous pathway is frequently 
traversed, its resistance is decreased so that the nervous impulses 
pass over it more and more readily. If a pathway has been 
recently used, it is in a highly permeable condition for a certain 
period of time, thus favoring the repassing of impulses along it. 
Primacy refers to the first neural connection made. Common 
opinion testifies to the ready recall to mind of first loves, first 
dances, first days in the army, first battles. First neural asso- 
ciations are evidently important. Vividness refers to the 
influence upon the fixing of neural connections of the bodily 
processes underlying emotional and affective experiences. In 
some way the nervous processes underlying these vivid con- 
scious states serve to aid certain neural processes and to inhibit 
others. We have met the fact constantly, first in the account 
of psychoanalysis and again in the account of emotions and 
affections. Thus if I see a wreck, hear a name, and experience 
horror at the same time, the total event is indelibly fixed in the 



SEQUENCE OF EXPERIENCES 289 

nervous system because of the emotional element, so that later 
on the experience persistently bobs up in consciousness. By 
emotional congruity we refer to the fact that all ideas that we are 
conscious of at any one time share the same emotional tone. 
Thus when our mood is predominately sad, melancholy thoughts 
dominate us; but when we are happy, depressing ideas have 
no chance to enter consciousness. In emotional congruity we 
must assume that the presence of an organic disturbance (the 
emotion) facilitates the arousal of the various neural activities 
that have been associated with it in the past. The result in 
consciousness is that only congruous ideas tend to appear so 
long as the particular organic disturbance lasts. It is probable 
that the law of cause and effect designates only a certain regular 
form of contiguity and so involves no new statement of neural 
relationships. "Matches," for instance, lead us to think of 
"fire," not because one is the product of the other, but because 
fire is an almost invariable accompaniment of matches. The 
law of similarity can best be stated in terms of nervous processes 
as follows: If a nervous process abed is active, it tends to be 
followed by activity cdef, because of the activity of the common 
elements c and d. Thus, on the conscious side, I see a lamp 
that suggests the image or the auditory- verbal perception "tree" 
because of a similarity in form, for a common nervous activity 
underlies the meaning "spreading top." 

In the second place, the secondary laws of association desig- 
nate relationships between conscious states. From this rela- 
tionship it has been possible to make a probable construction 
of the neural activities that underlie them. When the sequence 
"war," "Belgium," etc., has once appeared in consciousness, it 
is possible by comparing the individual terms to detect relations 
of recency, frequency, similarity, etc. These relationships do 
not precede the terms and accordingly call them forth; they 
appear after the terms are in consciousness. The causal factors 
lie, as we have indicated, in the nervous system. 



2go GENERAL PSYCHOLOGY 

Total and Focalized Recall. — James and Calkins have 
emphasized the practical importance of the two types of asso- 
ciation termed total, or concrete, and focalized, or partial, recall. 
If one were to refer to persons on the basis of the character of 
the sequences of conscious states usually present, one would 
speak of literal and clever people. In the first case there is a 
mechanical succession of conscious state upon conscious state 
with practically the whole of the first influential in recalling 
the second. Such an association is represented well by the 
sequence of letters of the alphabet, a, b, c, d, etc., where the 
appearance of one calls forth the next. It also appears in those 
reports of events given by persons who enumerate point after 
point without evaluation. The garrulous man and the child of 
eight belong here, for their conscious sequences are prone to be 
founded upon the relatively superficial. This is beautifully illus- 
trated in a passage quoted by James from Jane Austen's Emma: 1 

" But where could you hear it ? " cried Miss Bates. " Where could 
you possibly hear it, Mr. Knightley ? For it is not rive minutes since 
I received Mrs. Cole's note — no, it cannot be more than five — or at 
least ten — for I had got my bonnet and spencer on, just ready to come 
out — I was only gone down to speak to Patty again about the pork — 
Jane was standing in the passage — were not you, Jane? — for my 
mother was so afraid that we had not any salting-pan large enough. 
So I said I would go down and see, and Jane said: 'Shall I go down 
instead ? for I think you have a little cold, and Patty has been wash- 
ing the kitchen.' 'Oh, my dear,' said I — well and just then came 
the note. A Miss Hawkins — that's all I know — a Miss Hawkins, of 
Bath. But, Mr. Knightley, how could you possibly have heard it ? 
for the very moment Mr. Cole told Mrs. Cole of it, she sat down and 
wrote to me. A Miss Hawkins — " 

Opposed to this type of association is the case of Newton's 
having the action of the earth suggested by a falling apple. 
This and fortunately most other cases of association are 

1 William James, Op. cit., I, 571. New York: 1890, 



SEQUENCE OF EXPERIENCES 291 

instances where one particular aspect of a given conscious 
state is related to the succeeding conscious state — cases of 
focalized associations. In an earlier example the study-lamp 
suggested trees by virtue of one characteristic, its form. On 
the neural side this is described as we have already stated in our 
account of association by similarity. The importance of the 
ability to think in this manner rather than in that of Miss Bates 
can readily be appreciated. 

Simultaneous Association. — So far we have discussed asso- 
ciation from the standpoint of the sequence of conscious states 
and the sequence of muscular responses (habits and instincts). 
There is also a simultaneous association both in the field of 
consciousness and in the accompanying field of behavior. I 
see an ink-bottle upon a table, or hear two tones sounding 
together. Later when I recall the bottle in consciousness it is 
recalled with the table upon which it still sits. Likewise the 
recall of one tone brings simultaneously its accompaniment. 
These simultaneous experiences are held together as conscious 
objects by the contiguity of nervous processes — a principle 
which is at work uniting the elemental parts of all objects of 
imagination, i.e., all centrally aroused conscious states. The 
main exception is where the simultaneity of parts is due to 
present stimulation by objects (light, sound, etc.) not produced 
directly by muscular or glandular activity. When, for example, 
I see a table, the top and legs are together because the light- 
waves so stimulate my eye and not because of association. In 
a similar manner when I touch a round, rough object, the round- 
ness and roughness (touch-kinaesthetic perception) are held 
together in consciousness by the external stimulus acting on the 
receptors. There are, however, many peripherally initiated 
processes (sensations and perceptions) that are held together by 
virtue of the associated action of nervous processes. Trembling 
is a cutaneous-kinaesthetic perception, the two elements of 
which result from inherited connections in the nervous system. 



292 GENERAL PSYCHOLOGY 

This is likewise true of all the complex conscious experiences 
which at any one moment accompany instinctive responses. 
Instincts, as we have seen, are co-ordinations of reflexes. One 
does not have, however, a single muscular or glandular action in 
fear succeeded by another, but one has many muscular and 
glandular activities at one moment succeeded by another 
complex response at the next moment. The co-ordination or 
association is fixed by heredity, not only between successive 
moments, but also between the elements composing any one 
moment. 

Where the muscular responses are acquired and are therefore 
habits, the same general statement holds. I sing a certain 
tone, or laugh a certain laugh. The simple tones and noises 
that make up these sounds are held together by virtue of the 
air-waves that stimulate my ear, it is true, but these air-waves 
are what they are by virtue of the acquired connections in the 
nervous system that make the special muscular contractions 
possible. These are the cases in simultaneous association that 
parallel the sensory and emotional sequences of successive 
association. 

Both types of association are constantly at work. One 
does not find first one and then the other. Conscious states 
as they occur are held together as units in cross-section (simul- 
taneously) as well as in longitudinal section (successively) . Our 
chief concern has been with the latter case. In extending the 
present account the most important comments will be made 
under the headings of "Memory" and "Thinking." 

REFERENCES 

Angell, James R. " Methods for the Determination of Image Type," 
Psych. Rev. Mon., XIII (iqio), No. 53, pp. 61-107. 

. An Introduction to Psychology. New York: 1918. 

Betts, G. H. "The Distribution and Functions of Mental Imagery," 
Teachers' College Contributions to Education (1909), No. 26. 



SEQUENCE OF EXPERIENCES 293 

Calkins, M. W. "Association," Psych. Rev. Mon., I (1896), No. 2. 
. First Book in Psychology. Fourth edition. New York: 

1914. 
Fernald, Mabel. "The Diagnosis of Mental Imagery," Psych. Rev. 

Mon., XII (1914), No. 58. 
Galton, Francis. Inquiries into Human Faculty and Its Development, 

pp. 57-133. New York: 1907 (Everyman's Library). 
Hunter, W. S. "A Reformulation of the Law of Association," 

Psych. Rev., XXIV (191 7), 188-96. 
James, William. Principles of Psychology, Vol. I, chap, xiv; Vol. II, 

chap. viii. New York: 1890. 
Pillsbury, W. B. Fundamentals of Psychology. New York: 1916. 
Titchener, E. B. Text-book of Psychology, pp. 396-428. New 

York: 1910. 



CHAPTER IX 

MEMORY 

Definition. — The term memory can be used in either of 
two ways. It may be used to apply to the general fact of the 
retention of the effects of past experience, or it may be restricted 
to a state of consciousness which I am aware of having experienced 
before. In the first sense the term memory is a characteristic 
of all matter. A stone that is chipped retains the scar. A 
wire that is bent once or twice is more easily bent the third 
time by reason of its other experiences. Likewise, pathways 
in the nervous system that are once active are more readily 
traversed by later nervous impulses; that is, we say their resist- 
ance is decreased. Retention, accordingly, is a purely physio- 
logical affair. Sensations of color, tone, touch, etc., are not 
stored up in memory as in a closet, for they do not exist at 
all after the stimulation ceases. During the period of retention 
the individual is unaware of "memories," the thing that does 
remain being the changed condition of the nervous system. 
When the particular nervous activity underlying the previous 
sensation is re-aroused, the sensation appears again, and if it 
is now recognized as a thing previously experienced, the case is 
one of memory consciousness. For example, I play the tone C 
on the violin. When the string ceases to vibrate the tone is 
non-existent. It is not stored up in some world of tone. In 
order to call forth the tone the violin must again be played. 
When I speak of forgetting, I refer either to the absence of a 
certain state of consciousness or to the absence of a certain 
nervous activity. To be forgotten, as we shall see, does not 
mean that no traces are retained in the nervous system, for 
it is probable that no retention is ever completely lost. For- 

294 



MEMORY 295 

getting, therefore, is not the opposite of memory. Any state 
of consciousness that is not now present is forgotten; but only 
those present states of consciousness that are recognized are 
moments of memory consciousness. Retention, therefore, is 
clearly a fundamental characteristic of nervous action, under- 
lying every phenomenon of behavior and of consciousness. 
Even instincts and reflexes, as we have seen, are retentions of 
inherited modifications of the nerve tissue. Plasticity should 
be placed beside retention as the other conspicuous attribute of 
nervous action underlying memory and all other conscious 
processes, for in order to retain it is first necessary that the 
nervous system be modifiable, or plastic, since it is the modifi- 
cation that is retained. Our discussion of these two topics 
will be in terms of learning, or habit-formation. 

Memory and Imagination. — Memory, according to our 
second definition, is any state of consciousness plus recognition. 
Since we shall study the nature of recognition in detail in the 
following section, it will suffice to describe it here as the attribute 
of familiarity, i.e., as the awareness of having experienced the 
object before. Defined in this manner, memory is a much 
broader term than imagination. An image is a centrally aroused 
conscious process, while memory includes peripherally aroused 
processes as well as those centrally conditioned. Sensations, 
emotions, affective processes, images, and concepts may all 
alike be cases of memory if, and when, they are recognized. 
Popularly one tends to hold that memories are composed of 
images. I sit and call to mind "mental pictures and sounds" 
of the past. I indulge in reminiscence, and I recognize these 
images as revivals of my own past experience. I may, however, 
hum a melody (a series of auditory sensations) and recognize 
that it, too, belongs to my past; or an emotion of fear may 
re-present itself and be recognized, that is, be felt as familiar. 
The sensory qualities need not be aroused by association, as 
the above illustrations would tend to suggest. I may, for 



296 GENERAL PSYCHOLOGY 

example, be carried by train through a countryside visited 
years before. Object after object comes into consciousness with 
that "tang of familiarity" which constitutes it a moment of 
memory. Imagination involves an initial impression, a reten- 
tion of nervous modification, and a recall, or better a reinstate- 
ment, of conscious material. If recognition is added, we have 
one case of memory. In addition, memory includes all cases 
of reimpression that are familiar, whether the reimpression is 
due to association or to the reappearance of stimuli because of 
conditions outside of the individual's control. 

Reoognition. — What is this characteristic of recognition 
which, sets off memory consciousness from non-memory con- 
sciousness? The essence of it is familiarity, a complex of organic 
and kinaesthetic data that is usually markedly pleasant. 
Titchener has suggested that it may be a faint form of the 
emotion of relief. The recognition may be no more than this 
vague and indefinite feeling, a consciousness of "at homeness" 
and of "ease" and "acceptedness." From this it may reach 
any degree of definition until the object is located accurately 
in time and place. A melody comes drifting into consciousness 
in sensory or in imaginal form. It is familiar, it is accepted as 
a bit of revived past experience, but it cannot at first be defi- 
nitely located. Little by little, however, if it is dwelt upon and 
attended to, related images and sensations are aroused in 
consciousness until perhaps suddenly and with great satisfaction 
the melody is recognized as one heard at the last opera. So 
complete may the recognition be that every little detail of the 
original setting may appear. Experiment, however, has 
proved that recognition need not involve images. Tones, 
colors, objects of any sort, may be recognized as having been 
experienced before, and yet the observer may be unable to 
detect any trace of imagery accompanying the experience. 
Although recognition is the best subjective guarantee of the 
accuracy of memory, yet it often fails, and we recognize as 



MEMORY 297 

old many objects that are new; however, once the object is 
accompanied by the characteristic of familiarity, then conscious- 
ness can produce no better evidence of its memory character. 

Experimental Studies of Recognition. — In the experiments 
whose problems and general results are now to be indicated the 
typical method of procedure is as follows: (1) Colors, grays, 
odors, tones, pictures, advertisements, nonsense syllables, 1 
whatever it be, the material for study is selected. (2) This 
selected material is now presented to the subject either serially 
or in pairs. (3) It may be presented from time to time until 
the subject has mastered it. And (4) at the end of any trial 
the material may be presented to the subject in the same 
arrangement in which it was given originally or in a different 
one, in either case mixed in with new material. The subject 
is now instructed to state which material and arrangement are 
familiar and which novel. He may also be requested to describe 
frequently and in great detail what is in his consciousness 
when he experiences "familiarity." This is an illustration of 
the introspective analysis by which the structure of conscious- 
ness is laid bare. 

Experimental studies of recognition have concerned them- 
selves chiefly with the following important problems: (1) The 
analysis and description of the recognition consciousness. We 
have pointed out certain of the conclusions reached in our pre- 
ceding section. (2) The relative accuracy of recognition and 
recall. The general result here has been to demonstrate that 
such material whose retention is so slight that recall is impos- 
sible may still be recognized when presented to the observer. 
Thus I may be unable to repeat a given stanza of poetry and 

1 Nonsense syllables were first invented by Ebbinghaus (1885), the 
pioneer student of memory, whose contribution we shall study under reten- 
tion. They are constructed of two consonants with a vowel between. The 
syllable so constructed must not be a word with meaning and it must 
suggest an actual word as little as possible. Examples are: rik, rih, Ian, 
sul, rue, bez. 



298 general psychology 

yet be able to pick out with a high degree of accuracy the 
proper stanza from other slightly varied versions. Recognition 
is thus possible with a less degree of retention than is recall. 
(3) The dependence of the accuracy of recognition upon the 
significance of the material. It has been shown that recognition 
is more accurate where the material used makes sense (advertise- 
ments, pictures, words) than where nonsense syllables are 
used. The difference undoubtedly lies in the relatively larger 
number of associations present in the more meaningful material. 
This increase in the number of associations makes possible 
readier arousal of the feeling of familiarity and accordingly 
facilitates recognition. (4) The relation of accuracy of recog- 
nition to lapse of time. The above principle accounts for the 
fact that the ability to recognize nonsense material decreases 
very rapidly at first and then more slowly, whereas the ability 
to recognize certain significant material undergoes hardly any 
loss with lapse of time. The ready reinstatement of the char- 
acteristic of familiarity under these last two conditions is 
further aided by the fact that meaningful material becomes 
closely associated with words, i.e., it becomes named. The 
name is long remembered and readily brings "familiarity" 
into consciousness. 

The Problems of Retention. — Retention, as we have said, 
is a purely physiological affair, the study of which is fundamental 
for an understanding of memory. Since, unlike recognition, 
the study of retention is objective, behavioristic, we do not ask 
the subject for a description of his consciousness. Other 
methods of investigation must be used, the following ones being 
most important: (1) We record the number of trials and the 
time it takes the subject to master a given amount of material 
so that he can recite it or otherwise reproduce it without error. 
Later, after a certain lapse of time, we have him relearn the 
material. The difference between the amounts of time and 
the number of trials of the first learning and the second is a 



MEMORY 299 

measure of the amount retained. The greater the effort 
required in relearning the less the retention is. This is the 
saving method devised by Ebbinghaus. By varying the con- 
ditions under which the learning and the relearning are done, it 
is possible to study the effects of such conditions upon retention. 
(2) A second method is that of recognition, the details of which 
we pointed out in the last section. (3) The method of paired 
associates, devised by Calkins and perfected by Mueller and 
Pilzecker, is as follows: The material is presented to the subject 
in pairs (of words, nonsense syllables, etc.). It is read through 
a specified number of times, and then the first members of the 
pairs are shown the subject in a changed order. He is now 
requested to recall their associated second members. Retention 
is measured by the length of time that it takes him to recall 
the material and by the proportion of right to wrong answers. 
Thus the series a-b, c-d, e-f, g-h, is shown to the subject 
one pair at a time, each for one second. After the fifth reading, 
let us say, the subject is then shown c, g, a, and e, and requested 
to recall the syllables associated with each. Here again varia- 
tions in the conditions under which the pairs are learned will 
result in changes in the scores, indicating the influence of the 
varied conditions on retention. A typical apparatus used 
for presenting the material in each of these cases is shown in 

Fig. 54- 

Not only is the problem of retention essentially a behavior- 
istic question, as we stated above, but it is essentially the prob- 
lem of habit. Habit is an acquired co-ordination of reflexes 
just as instinct is an inherited one. More simply stated, habit 
is an acquired form of muscular or glandular response. Under- 
lying it there must be an acquired connection of nervous 
elements. Ordinarily when we think of habits we tend to 
think of movements of the hands and feet as in writing and 
dancing, but speech is also a habit, and the same principles 
apply to both instances of habit-formation. To connect 



300 



GENERAL PSYCHOLOGY 



one sound (cat) with another (dog) is as much a case of habit- 
formation as the connection of the different steps in a dance. 
Where two or more trials are necessary before the connection 
can be made, what is learned in the early trials must be retained 
in order that learning may be completed. Since retention, 
therefore, is as necessary to the parts of a habit as to the com- 
pleted form of response, our study of it consequently covers the 




Mac 2 b 



[ Otsl 1 

HO 




Fig. 54. — Wirth's memory apparatus. This apparatus makes pos- 
sible the serial presentation of material to be learned. The exposure time 
can be accurately controlled. 



learning process and the nature of forgetting. Most of the 
experimental work has been done upon language habits using 
two methods: studies of associating words together by employ- 
ing poetry, nonsense syllables, and similar material; and studies 
involving words or gestures to indicate other sensory material 
employed (odors, tones, etc.). Some work has been done upon 
non-language habits. Here the work has concerned the ques- 
tion of the acquisition of skill in typewriting, telegraphy, 



MEMORY 301 

shooting, running the maze (rats), etc. Both classes of problems 
are true habits. Both are in an equal degree acquisitions of 
skill. 

Conditions Favorable to Learning. — Experiment has shown 
that the following factors hasten learning: absence of fatigue, 
concentrated attention, pleasure, rhythmical material, an 
optimum rate at which the material to be worked up into a 
habit is presented, presence of significant meaning in the 
material, practice, distributed effort, the use of the whole 
as opposed to the part method, intention to remember, and 
the absence of interfering habits or associations. Since it is 
inexpedient to present here the data that go to substantiate 
all of these statements, comment will be made only upon a 
few. In each case the student will do well, however, to plan 
out an experiment suited to the investigation of the influence 
of each factor upon habit-formation. 

Learning Significant versus Nonsense Material. — Signifi- 
cant material, i.e., prose, poetry, pictures, etc., is more readily 
memorized than an equal amount of nonsense material, and, 
moreover, it is better retained. Thus Radossawljewitsch, 
working with the saving method above described, found the 
relative retention of poetry and nonsense material to be as 
follows: 



Period since learn- 
ing was completed 


Per cent of non- 
sense material 
retained 


Per cent of poetry 
retained 


5 minutes 


98 


IOO 


20 minutes 


89 


96 


1 hour 


71 


78 


8 hours 


47 


58 


24 hours 


68 


79 


2 days 


61 


67 


6 days 


49 


42 


14 days 


41 


30 


30 days 


20 


24 


1 20 days 


3 


. . 



302 GENERAL PSYCHOLOGY 

Significant material owes its advantages to its large number of 
associations, its superior interest, and the groupings into phrases, 
clauses, sentences, and topics that it contains. Consequently 
its memorizing does not involve so much de novo learning as 
does nonsense material, for many of the desired associations 
are already set up before the learning begins. In order to 
utilize these preformed associations that underlie meaning, the 
subject must grasp the idea involved in the material presented, 
thereby accomplishing much of the learning. Sheer frequency 
of repetition, however, must complete the acquisition. Since 
the amount and complexity of meaning in significant material 
vary greatly, learning and retention, consequently, vary greatly. 
It was to control this factor and make the meanings of all 
material on a par that Ebbinghaus devised nonsense syllables. 

Remote Associations. — We have seen that significant 
meaning is an aid to learning by virtue of its effect in grouping 
certain portions of the material into larger units than words. 
However, associations are formed not only between immediately 
succeeding parts of the material (language or non-language 
habits) but also between remote parts. The clearest cases in 
non-language habits are instances of the actual elimination of 
certain intermediate responses — usually referred to as the "elimi- 
nation of random movements." Thus a rat in learning to run 
a maze (see Fig. 4, p. 23) (1) runs slowly along the true pathway, 
(2) turns into a cul-de-sac, (3) turns and runs out, and then (4) 
continues along the true pathway. In practically every case 
the animal finally learns to associate 1 and 4, eliminating 2 and 3. 
The omission of the cul-de-sac may first occur accidentally and 
then be repeated as a result of pleasurable results and recency, 
until frequency finally completes the learning. Another type 
of remote association may also be cited, food, e.g., secured at the 
end of the maze soon furnishes the animal a motive for vigorous 
and purposive efforts at the beginning of the maze where at 
first only curiosity and random wandering were manifested. 



MEMORY 



303 



Experiments upon language habits using nonsense syllables 
have made possible a more detailed understanding of these 
remote associations. Ebbinghaus tested the matter in the 
following manner: He constructed six series of 16 nonsense 
syllables each, which the subject repeated until he could repro- 
duce them without error. Twenty-four hours later the syllables 
composing each series were rearranged and then relearned, the 
rearrangements consisting in placing side by side syllables that 
had originally been separated by i, 2, 3, or 7 intervening syl- 
lables, and also a series where the first and last syllables were 
retained in place and the others rearranged by chance (referred 
to in Table 2 as "permutation of syllables"). When these 
rearranged series were learned after the twenty-four-hour period, 
the amount of time saved in the relearning was an indication of 
the amount of association between the remote pairs. The 
following table taken from Ebbinghaus 1 indicates the results: 



TABLE 2 

(The numbers of the four middle columns denote seconds) 



Number of the 
intermediate sylla- 
bles skipped in the 

formation of the 
derived series 


Time for 

learning the 

original series 


Time for 

learning the 

derived series 


Saving of 

work in 

learning the 

derived series 


Probable 

error of 

saving of 

work 


Saving of 
work in per- 
centage of 
original 
learning time 


O 


(1,266) 

1,275 
1,260 
1,260 
1,268 

1,261 


(844) 
1,138 
1,171 
I,l86 

1,227 

1,255 


(422) 

137 

89 

73 
42 

6 




(33.3) 

10 8 


I 


±16 
±18 

* 7 
^13 


2 


7.0 
5-8 
3-3 

0.5 


* 


7 

Permutation of 
syllables. . . . 



From this it is apparent that the strength of the association 
between remote pairs is dependent upon the extent of their 
remoteness. The far-reaching effects of association shown by 

1 H. Ebbinghaus. Memory, p. 106; trans, by Ruger and Bussenius. 
New York: 1913. 



304 GENERAL PSYCHOLOGY 

this test serve to hold conscious states and muscular responses 
together in a thoroughgoing unity. In the following sections 
on "Habit-Interference" and "Transfer of Training" we shall 
see in detail other ways in which experiences interact. 

Habit-Interference. — It is a matter of common knowledge 
that many habits interfere with the formation of new ones. If 
I have a habit of securing a book from a certain shelf, it is diffi- 
cult to shift and begin taking it from another. Habits of all 
kinds are hard to change, for they represent firmly intrenched 
pathways in the nervous system over which nerve impulses 
flow most readily. Early in the experimental study of memory 
it was shown that if a series of nonsense syllables, A, was 
associated with another series, B, the association of A with a 
new series, C, was impeded or interfered with. This agrees 
with the familiar observation that if two names are equally em- 
ployed, one is often unable to recall either when occasion arises. 

There is an additional type of interference in language 
habits that is worthy of notice, the phenomenon of retroactive 
inhibition. Associations in the nervous system require a certain 
interval of time in which to "set," and if this interval is not 
forthcoming because of the too early onset of new associations, 
the first ones are retroactively inhibited. Students taking 
lectures meet this phenomenon constantly. The professor 
makes a point, but before the point can be assimilated another 
is brought forward and insistently emphasized, with the result 
that the former is forgotten. 

In the field of habits other than those of language, inter- 
ference is equally prominent. With animals below man, 
Hunter and Yarbrough have shown and Pearce has confirmed 
the fact that interference is strikingly present in the learning 
of rats. If rats are trained to run to the right through a box 
when a certain noise or light is given and to the left for silence 
or darkness, it is extremely difficult to reverse the behavior for 
slightly different noises or lights. The former writers have 



MEMORY 305 

shown also that two habits in response to very similar stimuli, 
although at first interfering, can soon be so thoroughly mastered 
that either may occur without any interference whatsoever. 
This confirms similar data secured in man by Munsterberg and 
Bair. 

Transfer of Training. — -Interference is the negative side of 
habit interactions, while transfer is the positive side. Does 
training upon one topic aid in the mastery of others? Is there, 
for example, any reason to believe that the acquisition of habits 
in mathematics will aid in the acquisition of habits in psy- 
chology? To what extent can one have a formal discipline 
that is valuable irrespective of the content of the habits to 
be acquired? Transfer does occur on a large scale. Habits 
that have been acquired do aid in the acquisition of new 
ones — in fact that is the only manner in which new habits can 
be built up. The aid' is not, however, the training of some 
mental faculty or capacity. One habit aids another to the 
extent that the two involve common elements. These common 
elements may be an inclusion of part of one habit in the next: 
e.g., the same nonsense syllables may occur in two series, or 
mathematical formulas may be present in psychology as well 
as in mathematics. Experiments that rule out such an over- 
lapping and that still show positive evidences of transfer are to 
be explained on the basis of common elements of the following 
type: more efficient attention, improved methods of study, 
increased resourcefulness, and application of economical 
methods of learning. 

Effects of Practice and Intention. — These two important 
conditions affecting the degree of retention are grouped together 
solely for the convenience of brief discussion. Individuals 
who practice the acquisition of any type of task improve their 
retentive capacity markedly. This improvement which may 
occur in memorizing nonsense syllables, poetry, scientific 
formulas, or other material is to be explained as a particular 



306 GENERAL PSYCHOLOGY 

instance of transfer where improved methods of learning are 
utilized. As a striking instance of practice effect we may 
give the case of Dr. Rueckle, a mathematical prodigy tested 
by G. E. Mueller (1913). After six years' practice on the stage 
he could memorize 204 digits in less than 9 minutes. Prior 
to this time it had required 18 minutes. His ability to memorize 
colors, syllables, etc., however, had decreased, a condition that 
was undoubtedly due to the interference with his new habit 
of learning. 

Experiment has shown that retention is better when the 
intention to remember is present at the original moment of impres- 
sion. This factor makes a large part of the difference between 
incidental and purposeful remembering, for one constantly sees 
and hears things that are not remembered, or that are recalled 
inaccurately. What type of figures are on the watch you 
carry? What is printed on the two-cent postage stamp? 
To retain well it is important to intend to retain. Not only 
is this necessary, but it is also important at the time of impres- 
sion to know how retention is to be tested. If the method 
of paired associates is to be used, the subject concentrates upon 
the connections by pairs. His attitude is different, on the 
other hand, if he is to be tested by the saving method. Stu- 
dents experience this difficulty when they attempt to master 
certain material without knowing the exact method by which 
they are to be examined. Furthermore, material learned by 
"cramming" for examination is usually forgotten early, for 
although the intention is for retention, still it is for temporary 
and not for permanent retention. The ability to acquire 
a large amount of information for a temporary use is of great 
value to lawyers, teachers, and individuals in many professions 
who meet situations of this type constantly. It is wise after 
all that most of the detail we learn should be soon forgotten! 

In experimental procedures the subject is ordinarily in- 
structed not to recall the material between repetitions. In 



MEMORY 307 

practical life, however, repetitions are constantly made from 
memory. This habit has both its advantages and disadvan- 
tages. Errors are prone to creep into these repetitions and so 
are sure to be fixed and retained as well as the correct material. 
Aside from this, however, Witasek has shown that the active 
recall required in these repetitions from memory is far more 
advantageous for retention than the more passive repetitions 
of the continued reading of the passage to be learned. 

The Whole versus the Part Method. — In our discussion of 
repetition the question at once arises concerning the method 
to be used in any problem of memorizing. When the average 
person attempts to learn a given amount of material he divides 
it into small units of material, and masters the task one unit 
at a time. He learns section by section in a psychology 
text or one stanza of a poem after another. It was shown by 
Lottie Steffens (1900), however, that memorizing by parts is 
less efficient than memorizing the material as a whole, i.e., 
reading over the entire task each time. This rule is even 
more applicable to significant material than to nonsense material. 
The gain comes, according to Meumann, largely in the fewer 
number of repetitions required and in the better retention. 
The whole method owes its advantages to the following facts: 
(1) it aids a uniformly distributed effort and a sustained atten- 
tion; (2) in meaningful material the total significance is best 
grasped by reading through the entire task; (3) part learning 
not only requires that each part (stanza, for example) be learned, 
but in addition special learning must be used to join the parts 
together; and (4) part learning produces many faulty associa- 
tions. If we use stanzas of poetry as the illustration, part 
learning associates the end of each stanza with the beginning of 
the same stanza and not with the beginning of the following 
one. The whole method is disadvantageous, however, when 
the material is so long that the effort involved is fatiguing and 
when the progress of learning is so slow as to be discouraging. 



308 GENERAL PSYCHOLOGY 

Furthermore, when the material is of very uneven difficulty, 
the method is bad to the extent that it requires as many repe- 
titions of the easy as of the difficult sections. In such cases 
it is best to underscore or otherwise mark the difficult passages 
so that extra effort may be concentrated upon them while 
the part already mastered may be skimmed easily and rapidly. 
As yet insufficient experimentation has been done to warrant 
an extension of the law to other than language habits, although 
work by Pechstein on rats and humans in the maze indicates 
its presence there. 

Distribution of Effort. — What variation is secured in the 
learning process by giving the trials far apart as opposed to 
close together? What effect does it have upon the economy 
of learning to distribute one's effort through a long period of 
time? The more the effort is distributed in time the less the 
number of trials required for mastery, and, vice versa, the 
more the effort is confined to a short period of time the greater 
the number of trials necessary for mastery. If fifty lines of 
poetry, for example, are read over once a day, or once every 
other day, fewer repetitions will be required to learn them than 
if they were read over two, three, or more times daily. It 
must be noticed, however, that distributed learning extends 
over a longer period of time than does concentrated learning. 
One method is economical in extent of time required, the other 
effects a saving in the number of trials. This is true not only 
for language habits as we have just outlined, but it is also 
true for other habits. Ulrich, as we saw on page 29, has 
demonstrated it for problem-box learning in the case of the 
white rat, and Lashley has shown it to hold for men in learning 
to shoot with the crossbow. The rule, it seems, however, is 
more applicable to large than to small masses of material. 

The explanation of the efficiency of distributed effort lies 
partly in the fact stressed under retroactive association and 
partly in facts formulated as Jost's law. Under the former 



MEMORY 309 

we may recall that it takes a certain interval of time for an 
association to "set" after it has once been made. If a second 
association is begun too soon, it interferes with the retention of 
the first. Distribution of effort permits this setting of 
synapses to continue uninterruptedly. Jost (1897) performed 
a series of experiments which indicate clearly that an older 
association is retained better than a newer one. Additional 
repetitions, moreover, strengthen the older association more 
than they do the newer one, e.g., if one memorizes fifteen non- 
sense syllables today and fifteen tomorrow, the former group 
will be remembered the longer (if both begin at equal strength) . 
Furthermore if I repeat each list once at the end of a week, the 
repetition will improve my memory for the older habit more 
than for the younger. Jost formulates his law as follows: 
"When two associations are of like strength, but of unlike age, 
repetition increases the strength of the older more than of the 
younger associations. When two associations are of equal 
strength, but unlike age, the younger fades more rapidly than 
does the older." 

The Training and Economy of Memory. — The importance 
of a consideration of the foregoing principles of learning lies in 
the fact that a trained memory is an economical memory, or, 
to put the situation in more adequate terms, a trained capacity 
for the acquisition of habits implies a training in economical 
acquisition. Whether or not a given method of habit-formation 
is economical depends largely upon the purpose for which the 
habit is to be formed: if one does not wish to retain for a 
long time, the intention to remember will be in accordance 
with that purpose; and if one wishes to economize the extent 
of time devoted to a task, he will concentrate, not distribute, his 
efforts. It often happens that one does not desire the ability 
to repeat a given material from beginning to end, the important 
thing being, perhaps, the ability to reproduce isolated points 
(parts). In such instances the part method is undoubtedly 



310 GENERAL PSYCHOLOGY 

more economical than the whole method. Consequently one 
must vary his methods constantly to suit changes in the pur- 
pose to be attained. To conclude the matter, we may say 
that the chief secret of a highly trained capacity for habit- 
formation is the ability: first, to formulate clearly the end to 
be accomplished; second, to concentrate attention upon the 
successive trials (repetitions) with the intention of accomplishing 
the purpose; and third, to suit the method used to the purpose 
to be attained. The greater apparent economy of adult memory 
is due to the increased experience, i.e., it lies in the increased 
wealth of meanings that makes the utilization of these three 
points possible in a high degree. 

Nature of Forgetting. — So far we have discussed retention 
from the positive side, that is, from the point of view of learning. 
When we have described the formation of various habits, we 
have spoken only of the individual associations or parts that 
have persisted from moment to moment and so have entered 
into the constitution of the final perfected habit. At each free 
repetition of the material that is to be worked up into a habit 
errors occur until the last stage of completed learning is attained. 
If the individual is learning nonsense syllables, he mispronounces 
and fails to recall properly, or he may even give syllables not 
on the list; that is, his vocal muscles make wrong movements. 
If he is learning to typewrite or to run a maze, he is continu- 
ally making wrong movements with his hands or feet. When, 
however, learning is completed, these erroneous responses have 
been eliminated, i.e., they are forgotten so far as that particular 
habit is concerned. This fact that all nervous processes which 
are not at the moment included in the present and ongoing 
habit are "forgotten," temporarily eliminated, is the funda- 
mental nature of all forgetting. Accordingly, as I write these 
lines, habits of eating and talking are eliminated, though later 
they may be reinstated or recalled. Since states of conscious- 
ness—sensations, images, emotions, etc, — 'accompany and are 



MEMORY 311 

dependent upon certain neural processes, if the neural processes 
are not included in the present ongoing habits and instinctive 
adjustments the conscious states in question are eliminated, 
j or gotten. 

In a coming section on "The Fixation of Arcs in Habit" 
we shall inquire into the detailed causes for the elimination of 
the erroneous responses during habit-formation. Our last 
few sentences, however, pointed out another and secondary 
form of forgetting. I am not now at the present moment in 
any real process of habit-formation. I am actually engaged 
in a habitual response, writing, i.e., I am now recalling this 
retained possibility into action. But there are very many other 
retained traces in my nervous system conditioning other possible 
habitual responses in which I might now be engaged. Why 
are not these habitual responses now reinstated, or, to put 
the matter the other way around, why are they eliminated at 
the present moment and forgotten? To state the case from the 
standpoint of consciousness, why am I here and now conscious 
of what I happen to be aware of and not of some other thing 
that is excluded, eliminated from consciousness? Why are cer- 
tain nervous processes and not others active at this moment? 
The question of forgetting or eliminating consequently pre- 
sents itself in two forms: (1) At the time neural associations 
(habits and instincts) are formed, why are certain neural associ- 
ations excluded? This is the primary and fundamental question. 
(2) Why at any one moment are many neural associations 
passed by and not recalled into activity? Why are they 
eliminated from the activity of the present moment? 

We shall discuss the former of these questions under the 
heading of "The Fixation of Arcs in Habit." Our comment on 
the latter question is as follows: A given state of consciousness 
or form of behavior is absent (forgotten) at the present moment, 
either: because of the absence of proper stimulus; because of 
the interference of other habits or neural processes; because of 



312 GENERAL PSYCHOLOGY 

the active repression of the forgotten item; or by virtue of 
disuse which has rendered re-excitation difficult. This last 
factor we must now discuss at greater length. 

Rate of Forgetting. — In what way, may we say, does for- 
getting proceed under the influence of disuse? Does one gradu- 
ally retain less and less as time goes on? Experiments began 
with Ebbinghaus, and they have shown that the loss in retention 
is greatest at first and then grows less and less until there is 
practically no further decrease. Ebbinghaus' tests have been 
repeated, notably by Radossawljewitsch, and have been 
confirmed except that the later students have found less rapid 
initial loss of retention. The following account summarizes 
the results of the two studies mentioned above upon nonsense 
syllables: According to Ebbinghaus, 55.8 per cent is forgotten 
at the end of an hour and practically 75 per cent after 6 days. 
According to the more reliable data of Radossawljewitsch 50 
per cent is not lost until 8 hours have passed, but most of this 
is recovered on the following day, so that a permanent decrease 
of 50 per cent is not found for 6 days. Popularly one regards 
the rapid learner as the quick forgetter. Much evidence has 
been secured, however, indicating that the contrary is the case 
and that the one who learns quickest also retains best. 

"The Fixation of Arcs in Habit." — We return now to the 
question of primary importance in our discussion of elimination. 
At the time neural associations are formed why are certain 
ones excluded? In this connection Watson has made use of 
the phrase "the fixation of arcs in habit" in referring to the 
essential factors that determine the fixing of acquired associa- 
tions between reflex arcs. For convenience we shall phrase our 
statements positively and speak of factors making for fixation 
and retention, though we are at the same time pointing out the 
factors that make for elimination and forgetting. If, for 
example, the more recent response tends to be repeated, we 
are also saying that the less recent tends to be overridden by the 



MEMORY 313 

more recent. Before enumerating and evaluating these different 
factors, let us formulate the steps in habit-formation in such a 
way that they will be as applicable to the formation of a type- 
writing habit as to the habit of repeating "My Country, 'Tis of 
Thee." 

Angell enumerates the following stages: (1) appearance of 
the stimulus, (2) random movements, (3) accidental success, 
and (4) elimination of all or of most of the random movements. 
I see the typewriter before me. My hands make clumsy, 
awkward, slow movements. My body as a whole is strained 
and perhaps contorted. From time to time I make proper 
movements and succeed in my writing. Gradually my awk- 
wardness vanishes, and I write accurately, at great speed, and 
with a minimum of effort. Let us take a language habit in 
order to illustrate the stages still further. (1) I see a list of 
French words and their English equivalents before me. (2) 
I repeat the list over and over with much bodily tension and 
with many random movements (mistakes) of the vocal organs. 
(3) From time to time I succeed in repeating portions of the 
list. (4) Errors are finally eliminated and the habit is complete. 
Many habits, however, as contrasted with these, are formed 
unconsciously, such as mannerisms of walking, talking, and 
dressing, which we suddenly notice are here, though of their 
coming we knew naught. It is important to note in our own 
present discussion that, with those habits whose formation is 
accompanied by consciousness, as the habit becomes more and 
more perfected, more and more automatic, consciousness dis- 
appears and ceases to accompany it. Finally I typewrite or 
repeat the French-English vocabulary list with practically no 
consciousness of what I am doing. 

Our fundamental question here is with reference to the 
elimination of random or unsuccessful movements. Three promi- 
nent psychologists have recently presented views that require 
comment: Thorndike (191 1), Carr (19 14), and Watson (19 14). 



314 GENERAL PSYCHOLOGY 

The factors making for the fixation of associations according 
to Thorndike are frequency (the law of exercise) and pleasure 
(the law of effect). According to Carr, they are frequency, 
recency, and intensity, and according to Watson frequency 
and recency only. In our own mind there is every reason to 
believe that frequency, recency, and the neural processes 
underlying pleasure are the important factors. Upon frequency 
all are agreed: a succession (contiguity) that is frequently 
repeated is thereby fixed. The neural connection underlying 
a movement recently made retains a low resistance and so 
tends to be retraversed immediately. The genuine dispute 
comes over the effect of pleasure. A child is given disagreeable 
medicine and thereafter refuses it. I make a mistake in my 
English-French vocabulary. Since it is unpleasant I do not 
make it again, thereby eliminating that random movement; and 
if the elimination is thoroughgoing I do not even have an image 
of the mistake made. But how can pleasantness and unpleas- 
antness, which are conscious processes, influence chemical or 
electrical processes in the synapses? This has been the uni- 
versal objection to rating affection as a causal factor, an objec- 
tion which is well founded. There can, however, be little 
doubt that something connected with these conscious states 
affects learning, that in some way the neural processes under- 
lying pleasure facilitate those other neural processes contiguous 
to them. We would therefore agree with Thorndike, but speak 
more objectively, and not refer to consciousness affecting the 
body. On the other hand, we would explicitly recognize the 
effect of pleasure's neural basis rather than, with Watson and 
Carr, 1 deny any effect. 

Curves of Learning. — So far in our account no comments 
have been made upon the progress of learning in the case of the 
formation of a specific habit. How does the elimination of 

1 1 believe, however, that Carr tends to include with intensity the bodily- 
disturbances underlying pleasantness and unpleasantness. 



MEMORY 



315 



random movements proceed? Is it a gradual process or is it 
one of relatively sudden changes? Most experimental studies 
of learning have contributed data upon this point, although much 
still remains to be done in the way of analysis of the factors 
determining the form of the learning curve as opposed to its 
length (the problem essentially of economical methods of 
learning). Curves presenting typical results were given in the 



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Fig. 55. — Learning curves for telegraphy secured by Bryan and 
Harter. 



chapter on "Animal Psychology" (p. 24) and in the chapter 
on "Instinct" (p. 167). The accompanying figure (Fig. 55) 
shows results secured in a classical experiment upon telegraphy 
by Bryan and Harter. The data upon which these curves are 
based were partly secured by questioning telegraphers and 
partly by experiment upon several individuals who were learning 
the trade. The latter subjects were tested at stated intervals 
during their learning period in regard to their ability to send 
and receive letters that did not make words, words that did 



316 GENERAL PSYCHOLOGY 

not make parts of sentences, and meaningful groups of words. 
The curves show the progress through weeks of practice in terms 
of the number of letters that could be sent or received per 
minute. Attention should be drawn to the following character- 
istics: (i) There is rapid progress in the first part of the curve 
indicating a relatively easy and consistent improvement. 
(2) The receiving curve remains below the sending curve for 
the greater portion of the learning. (3) The receiving curve 
shows a period of little progress, or a plateau. (4) Each curve 
tends finally to reach a level of little progress— the level of 
final ability. In explanation of the second characteristic 
Bryan and Harter present many factors that we cannot list, 
but all of which indicate the greater difficulty of receiving. 

The characteristic of chief interest is that of the plateau, 
which results from a slowing up in the relative rate of progress. 
This feature is found in innumerable cases of learning. One 
begins to play tennis, for example, and advances splendidly 
for a time. Then try as one will, his serving remains inaccurate, 
or he will return the ball out of bounds. If effort continues, 
however, this plateau will be passed perhaps in a sudden burst 
of ability that carries one to a much higher level. The same 
is true in chess, in golf, in typewriting, and in other habits. 
Some curves do not show plateaus, such as the sending curve 
given on page 315 and the maze curve on page 24. Plateaus 
may be due to any one of many factors of the following type: 
discouragement, poor physical condition, lack of effort, use of 
inappropriate responses, and the formation of subsidiary habits. 
The last point is the one stressed by Bryan and Harter, receiving 
being a complex or hierarchy of habits in which progress depends 
upon the mastery of the responses of least complexity. Habits 
must be built up for letters, words, and- word-combinations. 
The first two are acquired easily but the higher language habits 
come more slowly. U A plateau in the curve means that the 
lower-order habits are approaching their maximum develop- 



MEMORY 317 

ment, but are not yet sufficiently automatic to leave the atten- 
tion free to attack the higher-order habits. The length of 
the plateau is a measure of the difficulty of making the lower- 
order habits sufficiently automatic." 1 

We have emphasized but one characteristic of learning 
curves, and we have presented only one experimental study out 
of many dealing with it. Mention might be made of the fact 
that peculiarities in the rises and falls of curves have been used 
to differentiate rational learning from that of a haphazard 
trial and error type, but our knowledge is as yet too inexact 
to warrant more extended comments here. Enough has been 
said, however, to indicate the type of problem that arises in the 
study of the progress of habit-formation or, negatively stated, in 
the progress of elimination of random movements. We must 
now turn to the question of the function of habits after they are 
formed. 

The Function of Acquired Modifications of Behavior. — 
Acquired modifications of behavior, habits, are automatic 
responses that are called forth by the presence of any of a certain 
class of stimuli. There are stimuli for writing, for reading, for 
talking, etc., each class calling forth its appropriate response 
which has been built up on the basis of plasticity and retention, 
as we have described. What functions do these acquired associ- 
ations perform? In answering this question we may well 
call to mind the answer to a similar one raised in the chapter on 
"Instinct," page 175, where we had to deal with inherited modi- 
fications of behavior. Instincts serve to adjust the organism 
to its environment in ways that have proved not too disadvan- 
tageous in the past history of the species. Likewise habits 
serve to adjust one to his environment in ways that have proved 
not too disadvantageous in his own lifetime. Each automat- 
ism, whether an instinct and inherited or a sequence of vocal 

1 W. L. Bryan and N. Harter, "Studies on the Telegraphic Language. 
The Acquisition of a Hierarchy of Habits," Psych. Rev., VI (1899), 357. 



318 GENERAL PSYCHOLOGY 

contractions giving rise to the sounds of nonsense syllables and 
so acquired, enables the individual to bring past experience to bear 
upon the present problems. Solutions that have once been 
worked out may now be applied without repeating the process 
of learning. Speech is a solution of the problem of inter- 
communication; running is the rat's solution of the food-getting 
problem; and the automatic association of cortical nervous 
processes that gives rise to the sequence of images "Battle of 
Arras, 191 7" is my solution of the problem "What is a recent 
decisive battle of the world- war?" In either of these cases the 
association has been set up by having the essential parts retained 
and the erroneous, random parts eliminated. These habitual 
responses are "set off" by the appearance of their stimuli 
(problems) without relearning. They thus conserve energy 
and increase the efficiency of response. This function of acquired 
forms of response has its fullest development in that highest 
type of human behavior, termed thinking, to a study of which 
we now turn. 



REFERENCES 

Angell, James R. Psychology. Fourth edition. New York: 1908. 

Book, W. F. "The Psychology of Skill," Univ. Montana Pub. in 
Psych., 1908, Bull. No. 53. 

Bryan, W. L., and Harter, N. " Studies in the Psychology and Physi- 
ology of the Telegraphic Language," Psych. Rev., IV (1897), 

2 7-53- 

. "Studies in the Telegraphic Language. The Acquisition 

of a Hierarchy of Habits," Psych. Rev., VI (1899), 345-57. 

Carr, H. A. "Principles of Selection in Animal Learning," Psych. 
Rev., XXI (1914), I57-65- 

Ebbinghaus, H. Memory. Trans, by Ruger and Bussenius. New 
York: 1913. 

Ladd, G. T., and Woodworth, R. S. Elements of Physiological Psy- 
chology, Part 2, chap. viii. New York: 191 1. 



MEMORY 319 

Meumann, E. Psychology of Learning. Trans, by Baird. New 

York: 1913. 
Myers, C. S. Text-book of Experimental Psychology. Cambridge: 

1911. 
Peterson, Joseph. "The Effect of Length of Blind Alleys on Maze 

Learning," Behav. Mon., Ill (191 7), No. 4. 
Pillsbury, W. B. Fundamentals of Psychology. New York: 1916. 
Thorndike, E. L. Psychology of Learning. New York: 1913. 
Watson, John B. Behavior, chap. vii. New York: 1914. 
Watt, H. J. The Economy and Training of Memory. New York: 

1909. 
Wylie, H. H. "An Experimental Study of Transfer of Response in 

the White Rat," Behav. Mon., Ill (1919), No. 5. 



CHAPTER X 
THINKING 

Introduction. — Our study of thinking involves an analysis 
that can only be slightly behavioristic, or objective. It is 
largely an introspective field where at the best one can only 
insist — and it is important to do so — upon analogous phenomena 
in the field of habit-formation and association. The problem is 
essentially, What is in consciousness when "thinking" takes 
place, and how does this content change from moment to 
moment? Although philosophy and psychology come most 
closely together in their account of this topic, we shall encounter 
from time to time certain fundamental differences between the 
psychological account and the traditional logical account. 
As we proceed, it will be well to keep in mind a definition of 
thinking as a purposive sequence of states of consciousness (Watt, 
1905, and Ach, 1905). 

The Nature of the Concept. — We have already become famil- 
iar with moments of consciousness termed sensations, images, 
and emotions, and we have seen that each possesses meaning. 
This meaning is the significance of the experience, that for which 
the moment of consciousness stands. If we speak from the 
point of view of the nervous system, meaning refers to those 
neural conditions that determine the nature of the organism's 
response. So far in our statements concerning meaning we 
have taken account only of those cases where the significance of 
a conscious moment is its reference to an individual object. It 
has been pointed out that a sensation of red may mean any one 
of a number of specific things — apples, or barn, or sunset. 
In a similar manner I may have a centrally aroused conscious- 
ness of red — an image of red — and it may mean (refer to 3 

320 



THINKING 321 

stand for) the same objects. An emotion of fear or anger may 
also mean any one of many specific things; for example, it may 
signify "need for immediate flight" or "the presence of the 
enemy" or "a case requiring moral combat." As opposed to 
these instances where the state of consciousness refers to an 
individual object, we must now recognize cases where the 
reference is to a class of objects. Here one finds general and 
not specific meaning. Any state of consciousness plus a general 
meaning is a concept. I may have a sensation of red plus the 
meaning "red is a warm color." The reference is not only to 
this sensation but to any red sensation, and it is therefore 
general. I may experience the emotion of fear plus the general 
meaning "fear is an unpleasant emotion," or there may be the 
vocal-motor sensation or image of the word fear plus the mean- 
ing "unpleasant emotion." In each case the total experience 
is a concept, and the state of consciousness to which the meaning 
attaches is said to carry the meaning. Any state of conscious- 
ness can be a carrier of a general meaning just as all states of 
consciousness are carriers of individual meanings. 

What can observation detect in my consciousness when I 
experience the concept "table"? I may be aware of the table 
which is actually before me stimulating my senses. The quali- 
tative content may therefore be either visual, tactual, kinaes- 
thetic, auditory, or any combination of these sensations. I 
need see or touch but a fragmentary portion of the table — a 
leg, a drawer, the top— any stimulation being sufficient to 
hold the meaning. The sensory material, however, which 
serves as a carrier of meaning need not be so concrete as in this 
case. It may be verbal, that is, I may have the kinaesthetic 
or the auditory vocal-motor sensation of the word table, or I 
may see the word. Furthermore, the quality may not be in 
sensory but in imaginal terms, such as an image of a part of 
the table, of its color, of its name. This image may be visual, 
auditory, or of any other type, depending upon the previous 



322 GENERAL PSYCHOLOGY 

sensory experiences of the individual. The nature of the quali- 
tative content, therefore, is entirely irrelevant, for the general 
notion " table" may be in any terms that are associated with the 
general meaning. 

What then am I aware of when I realize that whatever sen- 
sory or imaginal experience may be present stands for tables in 
general? This is a most difficult question to answer. I find 
that if attention dwells on the term, case after case of individual 
tables appears in the focus of consciousness as a result of associa- 
tion. This condition will, if I doubt, convince me that the 
term is a general one. Only in cases where doubt arises, 
however, do these associated examples appear, for ordinarily 
in thinking concept follows concept. The awareness of their 
general meanings is there; and yet no illustrative instances are 
aroused. Here the general meaning is represented in conscious- 
ness in the terms of kinaesthetic sensations arising from motor 
attitudes, which one can often describe, for example, as incipient 
gestures of assent or acceptance. We shall have a further word 
to add concerning this subject in the section on "Conscious 
Attitudes." 

The Formation of Concepts. — In tracing the formation of a 
concept one is concerned with the origin and growth of the 
general meaning. Our understanding of this will be aided by 
calling attention to analogous phenomena in the field of behav- 
ior. Instincts and habits are generalized forms of response 
applicable to (or aroused by) any one of a given class of stimuli : 
eating is aroused by any object of food; the habit of type- 
writing applies to any given machine; fear and joy are aroused 
by any one of certain classes of objects. One may pursue the 
analogy as far in the animal scale as the amoeba. A negative 
tropism is a generalized form of response applicable to any one 
of a large number of stimuli. In a previous chapter we saw the 
impossibility of indicating the exact way in which instincts 
originated, but a fairly complete sketch was made of the process 



• THINKING 323 

of habit-formation. The development of a general meaning is 
essentially the growth of a habit, each constituting a case of 
learning. Most concepts are formed gradually, unconsciously, 
by the method of trial and error. We may suddenly realize 
that we have quite definite ideas (concepts) of right and wrong 
of tables and chairs, and yet be quite unable to describe the 
process of their development. The factors at work are the 
same that we found in all cases of learning — frequency, recency, 
vividness, pleasantness, and unpleasantness. In concept- 
formation, as is the case with other habits, perfection is seldom 
attained. A rat learning to run a maze, or a child learning to 
write, may make the same useless, random movement so often 
that it becomes fixed and included within the completed habit. 
Likewise in the formation of the concept one may meet a cer- 
tain situation so often that it is included within the concept by 
virtue of sheer frequency. Suppose that we are dealing with 
the concept picture. It may quite well be that all the pictures 
that I have seen are on paper. The meaning paper may there- 
fore become included within the general meaning picture, 
although it is an irrelevant detail attached to the concept 
picture on the basis of frequency — a situation which is on a 
par with random movements in motor habits. Furthermore 
the concept of picture, that is, one's definition of a picture, may 
fail to include certain essential facts (associated meanings) 
because no necessity for their inclusion has ever arisen. Such a 
concept, or general meaning, is not so much wrong as it is 
inadequate. The same statements hold for habits in general. 
For example, my typewriting habit (series of associated motor 
responses) may be applicable only to a certain class of machines, 
because it is only this class that has entered my experience. 

A brief sketch of the growth of a concept may make the 
situation more concrete. An individual is shown an object 
and the word ball is spoken to him. With a certain number of 
repetitions this association becomes fixed and the object 



324 GENERAL PSYCHOLOGY 

"means" ball. An apple may soon be encountered and because 
of its form may also mean ball. This is an error, a random 
movement, and is eliminated either as a result of parental 
instruction or on the basis of further experience which indicates 
that the apple means food whereas balls do not mean it. Vari- 
ous kinds of balls are met — large, small, soft, hard, and vari- 
• colored. Each calls forth the meaning ball, and frequency 
fixes the association in the absence of any factor tending to 
break up or discourage the association. At no stage does the 
child reason about the matter. At no time does he say, so to 
speak, "This new object must be a ball for it has the character- 
istics common to all the balls I know. It is round, can be 
thrown, etc." The formation and the elimination of associa- 
tions between objects and meanings go on unconsciously in 
the vast majority of cases even with adults. Only occasionally 
does one set out explicitly to construct a definition, or concept, of 
a given class of objects. Thus a biologist may seek a correct 
conception of the species amphibia. Here he will assemble at 
one time all of the known data bearing upon amphibia-like 
animals. From the data the common characteristics will be 
abstracted and serve as a general meaning when associated 
with the name of the class. Although this process of concept 
formation may be vividly conscious, it remains, however, 
subject to the factors conditioning all learning. The question 
now arises concerning the value of these concepts whose for- 
mation we have studied. 

Values and Limitations of Concepts. — The chief value of 
concepts lies in the increase in efficiency and economy of 
effort that they make possible. In order to make a statement 
concerning chairs, it is not necessary to re-see all chairs or even 
to call them up in imaginal terms. All that is necessary is the 
ability to reinstate in consciousness the concept chair which 
the experience of the individual has evolved as the adequate 
substitute for the individual awarenesses of chairs. Included 



THINKING 325 

in the general meaning of this concept are all of those character- 
istics common to chairs which have been found essential to any- 
thought concerning that entire class of objects. The concept 
thus represents a short cut in mental and neural processes. 
This statement becomes clearer by contrast with a description 
of the concept given by the great English psychologist, James 
Mill (1829): 

The word, man, we shall say, is first applied to an individual; 
it is first associated with the idea of that individual, and acquires the 
power of calling up the idea of him; it is next applied to another 
individual, and acquires the power of calling up the idea of him; 
so of another, and another, till it has become associated with an 
indefinite number, and has acquired the power of calling up an 
indefinite number of those ideas indifferently. What happens ? It 
does call up an indefinite number of ideas of individuals, as often 
as it occurs; and calling them up in close connexion, it forms them 
into a species of complex idea 

Have we not the idea of an army ? And is not that precisely 
the ideas of an indefinite number of men formed into one idea? 
Have we not the idea of a wood, or a forest; and is not that the idea 
of an indefinite number of trees formed into one idea ? . . . . 

The following is, then, a very natural train: — 1, The name occurs; 
2, the name suggests the idea of one of the individuals; 3, that idea 
suggests the name back again; 4, the name suggests the idea of the 
second individual. All this may pass, and, after sufficient repetition, 
does pass, with the rapidity of lightning .... all in that small 
portion of time of which the mind takes no account. 1 

Careful observation of the nature of the concept, however, 
fails to verify Mill's logical analysis of what the concept ought 
to be. It is a much more unitary experience than Mill credits it 
with being. The many detailed mental processes which he 
mentions are eliminated during the process of concept formation. 
The very fact that all of these minutiae of past experience can 

1 James Mill. Analysis of the Phenomena of the Human Mind, Vol. I, 
chap, viii, pp. 204, 205, 209. London: 1829. 



326 GENERAL PSYCHOLOGY 

be replaced by one state of consciousness plus a general meaning, 
as we have indicated, constitutes the peculiar value of a concept 
and of conceptual thinking. 

The limitations and dangers in the use of concepts grow out 
of the very characteristics that are their chief advantage. To 
stand for a class of individual objects, to include all of their 
essential characteristics, is to ignore the attributes peculiar to 
the specific object. Thinking, which largely goes on in terms 
of concepts, is therefore prone to overlook exceptions and to 
regard concepts as the "real" objects. Laws, customs, and 
tradition, as we outlined in our chapter on "Social Psychology," 
are conceptual systems, general formulas, which are applied 
to individual cases of behavior. It is a familiar fact in social 
life how conservative and slow to change custom is. The same 
condition holds in the intellectual life of the individual. Con- 
cepts represent fixed associations or habits that have proved 
more or less practical in the person's experience. They there- 
fore resist change and hence may lead to serious maladjustment. 
The capacity to review the accumulated institutions and facts 
of civilized man and then to form new and serviceable concepts 
is rare and is the property of genius. The other defect of 
primary importance is exemplified in the history of philosophy. 
Philosophers have carried on great controversies over the 
probable realness or unrealness of concepts. Is there such an 
existence as chair or table in general, or are these merely names? 
It is aside from our domain to discuss the question, but it serves 
to redirect our attention to the importance in practical experi- 
ence of the standardized meaning. Earlier (p. 221) we pointed 
out in the case of our perception of a rectangular table that the 
configuration of the sensory qualities was not rectangular but 
oblique, and that the perception was a pronounced instance of 
the supplementation of sensory qualities by centrally condi- 
tioned standard meanings in the light of which the table was 
viewed. These meanings conditioned the content of conscious- 



THINKING 327 

ness by actually excluding the awareness of the obliqueness of 
the table. Likewise there are standardized general meanings or 
concepts which greatly influence our thought and manner of 
looking at things. The conventional definitions of men, chairs, 
and books, for example, which we apply to individual percep- 
tions or images as they enter consciousness, prevent us from 
attending to the exact nature of our experiences as they present 
themselves. We thus see those things that are expected. The 
concept "soldier" applied to a man, for example, classifies him 
in a certain definite way and leads one to ignore the individual's 
other possibilities. Or, again, one customarily regards a book 
as an object to be read and so does not see that it is just as 
truly a small quantity of matter whirling annually about the 
sun. It is in this manner that customary concepts determine 
the nature of our experiences. 

All that has just been said concerning concepts is equally 
applicable to habits of all sorts, because concepts are but the 
conscious side of certain neural associations. Habits — -type- 
writing, playing the piano, drinking, etc. — 'are fixed and difficult 
to break. They are modes of response called forth by various 
situations — often wrongly called forth. For example, one 
plays the piano when the response to the situation might better 
be an activity of the language habit. From the conscious 
side his error is one of judgment, i.e., he has classified the situa- 
tion under the wrong concept. 

The Nature of Judgment. — With the topic of judgment we 
pass to the consideration of a more complex experience than we 
discussed in the previous section on concepts. Popularly, to 
judge is to pronounce upon some question, to settle issues or 
doubts. This judgment as formulated in language may be 
termed a proposition or statement. My eyes turn toward the 
desk and I say, "That is an inkwell," or, "The ink is black." 
These are completed and fully elaborated judgments in language 
form. I might have experienced the same thought, however, 



328 GENERAL PSYCHOLOGY 

without verbal accompaniment. In this case there would have 
been the visual perception of the combination of sensory quali- 
ties plus the meaning inkwell. In the second judgment above 
there are really two judgments, whether put in language form 
or not: "This is ink," and "It is black." Judgment may 
therefore be defined as the assignment of meaning to the given 
qualities. In the elementary form of judgments of identifi- 
cation it is impossible to distinguish between the conscious 
moment as sensation and as judgment. The same is true for 
emotions, affective processes, and other states of consciousness. 
In the non-verbal forms of judgment the demonstrative 
particles (this, that, there, here, etc.) are usually represented by 
cutaneous-kinaesthetic sensations or images involved in such 
activities as pointing, nodding, focusing and turning the eyes. 
So far as I recognize or identify the present complex of kines- 
thetic and organic sensations as fear, so far do I assign meaning 
and therefore experience judgment. 

Experimental Studies of Judgment. — Practically the only 
specific problem concerning the judgment that has been experi- 
mentally handled is that of its structural analysis. What can 
carefully controlled observation say of the content of conscious- 
ness during the moments when fully elaborated judgments 
occur? The general method is to present the observer with a 
problem for solution, a report of the experience being carefully 
given upon the completion of the task. Subsequent observa- 
tions may be directed to special parts of the mental process 
involved, varying according to the interests of the experimenter. 
The problems used have been of two general types: (i) those 
requiring a discrimination and comparison of various sensory 
data, such as colors, tones, or weights (Schumann, 1898; Martin 
and Mueller, 1899; Whipple, 1901); and (2) those requiring 
the understanding and solution of certain "thought" material 
(Marbe, 1901; Binet, 1903; Watt and Ach, 1905; Buehler, 
1907; and Woodworth, 1906-7). In the first method the 



THINKING 329 

subject may be given a series of weights to lift in order to deter- 
mine which is the heavier. Standard conditions are imposed 
to minimize the effect of extraneous factors such as suggestion, 
relative position of weights, etc. If the material used is sound, 
the observer may be given one tone of constant pitch to compare 
with the pitch of a variable one. The subject is instructed to 
observe and report upon the content of consciousness at the 
moment the judgment — '"higher," "lower," or "equal" — is 
made. In the second method the subject is given a list of 
aphorisms and other sentences and is requested to read them 
understandingly and then to report upon the nature of the 
consciousness involved; or he is given a series of two relation- 
ships and requested to supply the third and then report (Wood- 
worth). An example of this type of material is as follows: 

Paris : France : : Athens : . 

The experimenter constantly makes an effort to select material 
for observation that is thought-provoking. 

These general methods, which we have outlined, are used in 
the experimental analysis of thought as well as in the study of 
judgment. The results secured by the investigations listed 
above lead us to consider the role played in these experiences by 
three factors: the absolute impression, the image, and the con- 
scious attitude {the awareness of the problem, or the Aufgabe). 

The Absolute Impression. — -When we speak of an absolute 
impression we are drawing attention to the difference between 
the relative and the absolute. Without reflection, for example, 
we term various objects hot or cold. The inkstand in front of 
me I say unreflectively is heavy, whereas the one on another 
desk is light. Here are judgments involving comparative 
values, but close observation indicates that no conscious com- 
parisons were indulged in. The inkstands give the impression 
immediately of being absolutely light or heavy, i.e., as belong- 
ing definitely on a certain side of the medium in a scale of 



330 GENERAL PSYCHOLOGY 

weight-intensities. In this manner we judge people to be large 
or small, lights to be bright or dim, tones to be high or low. "As 
lights go in my experience" or "as lights are usually found in 
laboratories," this one is dim. If I am questioned, associations 
may be aroused and conscious comparisons made; otherwise 
the stimuli give the "absolute impression" of the values assigned 
them. This impression is apparently made possible by the 
gradual and unconscious development of an association which 
stands for the typical or average experience to be expected. The 
type probably rarely enters consciousness but must be thought 
of as the neural counterpart of a possible conceptual experience. 
New awarenesses are unconsciously judged in terms of this 
standard or concept; and in so far as the process takes place 
automatically, the experience makes an absolute impression of 
heaviness. Martin and Mueller in their study of lifted weights 
■ — where a standard and a variable weight were tested and then 
compared as to heaviness — -found a tendency to judge the vari- 
able as heavier, equal, or lighter before the standard weight was 
lifted. The fact is to be explained by the unconscious influence 
of the average-weight experience. 

Whipple in his study of tones analyzes for us a case of 
absolute impression and indicates how certain motor attitudes 
carry the meaning of "higher" or "lower" in pitch. These 
motor attitudes are represented in consciousness in the form 
of kinaesthetic, cutaneous, and organic sensory complexes. 
Whipple says: 

Judgments of "higher" and "lower," made without conscious 
reference to the image, are largely analyzable into complexes of 
strain sensations, with less prominent visual and organic elements, 
set free neurologically by the variable stimulus. The two chief 
factors, feelings of tightening and relaxation for "higher" and 
"lower" respectively, were reported throughout the tests with dis- 
crete tones, and were also well brought out with the wide differences 
used in the reaction method. We believe that these strains, which 



THINKING 331 

are especially noticeable in the chest, throat, eyebrows, scalp, and 
about the ears, are explicable as symbols for "upness " and downness" 
in the tonal continuum, set up by every-day experience, especially 
in executing and listening to music. 1 

The Role of the Image in Judgment and Thinking. — The 

quotation just made from Whipple should remind us of the 
earlier discussion of recognition. Neither there nor here in our 
study of judgments was it found that images were necessary. 
In both cases it has been shown that, although present, the 
image may appear to play a negligible and irrelevant role. 
The addition of imagery to the content (sensation, image, 
emotion, etc.) that is recognized or that is judged is unnecessary, 
though in many individuals, perhaps, images may occasionally 
or even frequently be used in recognizing or in judging. 

One may find various reasons for the assignment to images of 
a peculiar role in acts of thought. Chief of these is the momen- 
tum of historical usage. The philosopher-psychologist, upon 
whose shoulders until recently rested the burden of advancing 
the subject, placed an extraordinary overemphasis upon vision 
and visual images. The consequences we saw above in our 
account of association. Visual sensations cannot be produced 
and controlled by the organism. It is to be expected, there- 
fore, that with vision occupying the center of psychological 
interest, thinking should have been regarded entirely as a matter 
of "ideas." These ideas were only images with the chief empha- 
sis placed upon the attribute of meaning. The point was not 
yet reached where a structural analysis of the attributes of 
experience could be carried through. Qualities were therefore 
largely ignored and stress laid upon meanings; and these were 
assumed to attach in cases of thinking to images only. Our 
discussion of association places us in a position to view correctly 

1 G. M. Whipple. "An Analytic Study of the Memory Image and the 
Process of Judgment in the Discrimination of Clangs and Tones," Amer. 
Jour. Psych., XIII (1902), 263-64. 



33 2 GENERAL PSYCHOLOGY 

the place of the image, and the results obtained from the 
experimental studies of judgment and thinking necessitate the 
following restatement of the role that it plays in our thought 
processes. 

To think is to experience a purposeful sequence of conscious 
states as opposed to a non-purposeful or random sequence such 
as constitutes reverie. The only qualification necessary is 
that a greater or lesser portion of this sequence must be com- 
posed of states of consciousness which are under the organism's 
control and which, therefore, can be revived at will. A pur- 
poseful sequence composed entirely of images is an act of 
thought; but it is only one case and perhaps with most individ- 
uals it is very rarely experienced. The sequence may be of 
sensations, affections, or emotions. The practical, actual 
instances of thinking involve usually an almost inextricable 
intermingling of these, with images thrown in here and there. 
Many of the components of an act of thought need not be under 
the organism's control; i.e., visual sensations are often an 
integral part of the sequence, and we know that the organism's 
control over visual objects (and often of numerous others) 
lies essentially in its ability to place itself before them. On 
page 336 is outlined an instance of a train of thought where 
this is the case. However, connecting and binding this type 
of material together are processes whose stimuli can be directly 
controlled — kinaesthetic and auditory qualities. 

The second primary reason for assigning images a peculia r 
role in trains of thought lies in the frequent profusion with 
which they appear when difficulties impede thinking. One may 
be proceeding fairly directly and easily toward the solution of 
a mathematical problem when suddenly a needed formula fails 
to arise in consciousness. Immediately a wealth of imagery 
may appear containing many possible suggestions — images of 
other formulas, and other problems, or imagery of the professor's 
face and manner, etc. Because of the prevailing interest in 



THINKING 333 

ideas as described above, attention has usually passed over the 
fact that a wealth of sensory, emotional, and affective material is 
also called out in these moments when difficulties arise. The 
large array of conscious states and motor responses thus initiated 
owes its origin to the diffusion of nervous excitement through 
widely scattered portions of the nervous system. The explana- 
tory principle so stated is similar to the law of direct nervous 
action used by Darwin to explain certain emotional expres- 
sions (see p. 190). Similar behavior occurs far down the 
animal scale. Whenever an organism is placed in a situation 
needing solution, first one and then another of its acquired and 
instinctive responses is called forth until the solution is reached 
or the animal is exhausted. The method is one of trial and 
error. Thus Thorndike found that a hungry cat placed in a 
box from which escape to food might be affected only by means 
of a latch would bite, scratch, and struggle until accidentally 
the solution was won. Such, furthermore, is the case with 
man. His actions may be controlled or spasmodic, but if they 
are consciously directed toward an end the awareness of them 
constitutes thinking. Out of the mass of organic responses and 
sensory, imaginal, emotional, and affective conscious material 
set free by the diffuse action of the nervous system, it is there- 
fore impossible to select imagery as the peculiarly important 
solution material. 

The Conscious Attitude. — The topic of conscious attitudes 
leads one at once into the heart of the problem known today as 
that of imageless thought, the experimental studies of which 
date from Karl Marbe's investigation of the judgment in 1901. 
The preceding discussion has indicated that in one sense image- 
less thought is an actuality, for thinking can proceed in terms 
of any conscious content. The so-called doctrine of imageless 
thought, however, postulates pure thought, pure meanings 
unattached to any qualitative content. It is said that after any 
given thought process has been analyzed into its component 



334 GENERAL PSYCHOLOGY 

sensory and imaginal elements, there still remains a phase 
termed variously the conscious attitude, a bare awareness, a 
naked elemental thought, an irreducible consciousness of 
relation. These processes are unanalyzable and cannot be 
described in terms of other conscious states. They must be 
experienced to be known. The subjects used in the experiments 
from Marbe to Buehler (1907) have reported this imageless 
thought in phrases as follows, the method used being described 
on page 330: "A conscious attitude appeared which signi- 
fied to the observer, 'This is to be nonsense.' — -'I was aware 
that this statement was false.' After the words of the spoken 
sentence died away, the thought appeared 'They are equal.' " 
I translate a typical observation from the experiments of Buehler 
in which the subject is instructed to answer when he under- 
stands, the time interval preceding the answer being measured 
and a description of the subject's experience being called for: 
" 'If you would have the fruit from the tree, do not pluck the 
blossoms.' — 'Yes (fs"). — The understanding appeared directly 
after the hearing. The ideas of fruit and blossoms were 
especially prominent. Thereupon the thought turned to 
the causality which exists between them, to their temporal 
relation, and to the awareness that and how the point could be 
transferred to human relationships. No images were present. 
Only the thought was present, that is, a beautiful picture 
(also without words)." Other observations of the same nature 
might be taken from Woodworth's studies of this topic. 

The doctrine of imageless thought as here set forth does not 
seem tenable when viewed in the light of more recent critical 
and experimental evidence. In this country Titchener's labora- 
tory in particular has performed similar tests in which the 
imageless thoughts have been shown to consist of sensory and 
imaginal components. From the theoretical point of view it 
has been urged (we think truly) that much of the experimen- 
tation which has yielded positive evidence has utilized problems 



THINKING 335 

of such a nature that answers could be given automatically. 
Our previous discussions have shown the importance of this 
criticism by indicating that all forms of consciousness tend to 
disappear with the increasing automatization of a response. 

The Aufgabe. — A genuine service has been performed by 
Watt in calling attention to the role in thought of the Aufgabe, 
or awareness of the problem. Watt's definition of judgment is 
similar to our own definition of thought: that is, a sequence of 
conscious states determined by the Aufgabe, or problem to be 
met. In many cases this Aufgabe has been in consciousness, 
and in many cases it still persists there during the process of 
judgment or thought. It is not merely, for example, the 
sequence of "cold," "water," and "shivering" which constitutes 
that sequence a judgment, but the train of conscious processes 
must be adapted to a purpose or end in view. Or, if we speak 
in terms of behavior, the sequence of responses must not be 
random, but must be co-ordinated for the attainment of an 
end (adjustment). "Cold," "water," "shivering," if they 
appear in consciousness as an answer to "the-result-of-stepping- 
off-the-bridge," constitute a judgment, or an act of thought. 
It will therefore be seen again that no sharp line of distinction 
can be drawn between what is and what is not judgment. 
All sequences, whether of consciousness or of behavior, are 
determined by certain factors; so the term judgment (or, with 
respect to behavior, such an odd term as "judgmental behavior") 
should be reserved for those cases where the determination or 
control of a sequence of conscious states is clearly adapted to a 
present problem. Accordingly spontaneous sequences, or free 
associations, are ruled out because, while they are determined 
by synaptic conditions, the determination is with reference to 
a situation dominant at an earlier date when the association 
was first fixed and not with reference to a present issue. 

Analysis of a Concrete Act of Thought.— Our preceding 
descriptions of the content of thought and of the factors making 



336 GENERAL PSYCHOLOGY 

for a sequence of contents have furnished us the necessary 
background for an understanding of much that occurs in a 
concrete act of thought. In our present account we shall 
follow Dewey. Dewey recognizes five steps in each completed 
act of thought: (i) a problem or conflict, (2) the definition or 
interpretation of the problem, (3) suggested solutions, (4) the 
testing of the suggested material, and (5) the final acceptance or 
rejection of a given solution. The last act is both the logical 
and the temporal conclusion of the process. Let us consider 
the following illustrations: I am quietly reading in the evening. 
Suddenly the lights go out. Here is a problem. My habitual 
responses are interrupted, and in order to continue my adaptive 
behavior a solution must be found. My first interpretation of 
the problem is merely one of "sudden darkness." I continue 
from now on until the end to make more detailed and explicit 
the exact nature of this "sudden darkness," each suggested 
solution being an attempt at successful redefinition. Let us 
say that the first suggestion is that the wires in the lamp bulbs 
are burned out. This would define the situation as "sudden- 
darkness - due - to - burned - out - bulbs - remedy - insert - new - 
bulbs." The suggestion may come in sensory or in imaginal 
forms. I instantly test out the offered solution, either by 
further consideration (thought) or by actual inspection of the 
bulbs. In the first case associated processes related to the 
problem enter consciousness one after another. Earlier 
experiences are recalled in detail; but suddenly it is realized 
that all the bulbs are not likely to burn out at once, and I 
conclude temporarily that they have not done so. Actual 
examination reveals the fact that the bulbs are intact. It is 
now suggested that the generator at the power-plant has 
stopped, for in the city concerned there are past experiences 
that render this judgment probable. I am about to rest 
content with this solution of the difficulty, when suddenly I 
experience the thought, "But this does not enable me to continue 



THINKING 337 

work." The insistency of the situation calls for further sugges- 
tions (random movements) until the possibility that the fuses are 
blown out appears in consciousness. No contradictory ideas 
intervene, and in a moment I am at the switchboard to verify 
the suggestion. The discovery that the fuses are really gone 
starts me on a search for others. When new ones are inserted 
the lights come on again. The actual appearance of the light 
is the final proof of the correctness or adaptive value of my 
judgment. In this manner one may describe any act of thought, 
the main steps of which are to be summarized as follows: 
first, a conflict or breakdown of responses due to a certain novel 
situation; second, the calling forth of all acquired and inherited 
responses of the organism until the problem is either solved or 
abandoned; and third, the acceptance of a given aroused 
response as the problem's solution on the basis of its ability to 
change the initial problem in the manner necessary to permit 
further adaptive behavior. In the illustration that we chose 
for analysis no striking instinctive behavior was involved. 
Let the organism, however, find itself in a difficulty involving 
food, self-preservation, or sex, and sooner or later the acquired 
associations will prove inadequate to adjust the individual so 
that, as a result, the instinctive responses need appear. These 
may or may not succeed. For example, a man caught in a fire 
may have suggested first one and then another mode of escape 
of which he had heard in times past. If these fail, he will 
undoubtedly be thrown into a panic of fear. His blind strug- 
gles now may accidentally free him of the problem; but if they 
do not there is no further recourse within the organism's control. 
The foregoing analysis has said little concerning the content 
of consciousness. It is to be understood that sensations, 
images, emotions, concepts, conscious attitudes, and Aufgaben 
are all at work. The latter in particular function by limiting 
the associations which are aroused to those that bear directly 
upon the problem to be solved. As we said above, it is the 



338 GENERAL PSYCHOLOGY 

unifying effect of the Aufgdben which changes a mere sequence 
of experiences into an act of thought. 

The R61e of the Syllogism in Thought. — -Logicians have placed 
much stress upon the syllogism as the typical formulation of an 
act of thought. The syllogism is composed of three judgments: 
the major premise, which states a general principle; the minor 
premise, where the particular object is referred to the general 
principle of the major premise; and the conclusion. There 
are many forms of syllogisms, but the following classical illus- 
tration may serve as typical of them all: 

All men are mortal. 

Socrates is a man. 

. * . Socrates is mortal. 

Any form of argument, any act of thought, can be cast into 
this form, so that the essential steps in the process are rendered 
distinct from each other and one is enabled to judge of the 
correctness of the conclusion. Logic has analyzed and classified 
the various types of errors under the heading of fallacies. These 
need not concern us here further than to point out that fallacious 
reasoning is non-adaptive behavior and as such is a genuine 
problem in the study of human nature. Not all purposeful 
sequences of conscious states will aid in the solution of the 
difficulty, or conflict, in which they arise. We may give two 
examples of fallacious thinking for the sake of further clarifying 
the matter, leaving the discovery of the error to the student: 

i. What are feathers? 

Light comes from the sun. 

Feathers are light. 

. ' . Feathers come from the sun. 

2. Why did the train stop? 

If the engineer sees a danger signal, he will 

stop the train. 
He stopped the train. 
. ' . He saw a danger signal. 



THINKING 339 

Although any act of thought can be cast in the mold of a 
syllogism, it does not follow that thinking actually takes place 
in that manner. Psychology has been primarily interested in 
the actual processes that occur in thought, while logic has been 
largely interested in the analysis of completed acts of thought. 
Pragmatic, or instrumental, logic as championed by James and 
Dewey has fought this tendency and has made logic more 
psychological. Practically never do we use a developed syllo- 
gism in our thought unless doubt arises concerning the validity 
of the conclusion. Thinking proceeds as a sequence of con- 
clusions. "All men are mortal" is itself a conclusion subject 
to proof and doubt; but in actual thinking when the con- 
clusion "Socrates is mortal" appears, the two premises are 
taken for granted. For example, I have the thought: "Socrates 
was a Greek philosopher. He was mortal. His death resulted 
from drinking hemlock." Each sentence puts into verbal 
form a judgment or conclusion, a certain meaning assigned to 
certain facts. Conclusion succeeds conclusion according to 
the laws of association and the Aufgabe of the moment. Sud- 
denly I myself or a listener questions or doubts one of the con- 
clusions stated. The proof offered is first a statement of a 
minor premise. Thus if "Socrates was mortal" is doubted, 
my first reply may be that Socrates was a man. If this fails to 
satisfy the doubter, I may either state another minor premise 
or go on to state a major premise, "All men are mortal." There 
is no one answer that must be given in reply to doubt, because 
any proof is valid that allays doubt and secures belief in the 
mind of the questioner. Therefore the premises that will satisfy 
one person may not satisfy another. Thus, according to 
the manner of individual with whom we are dealing, we might 
have proved Socrates mortal by citing any of the following 
judgments: (a) He lived about 2,000 years ago. (b) Win- 
delband's History of Philosophy says that he is dead. 
(c) All of the histories of philosophy agree that he is dead. 



340 GENERAL PSYCHOLOGY 

Let us take another illustration. If the statement (conclusion) 
that "honesty is a virtue" is doubted, it will take one line of 
premises to prove it to a young American, another to an adult 
American, and still another to an uncivilized man. Proof 
must always be approached from the doubter's point of view and 
will vary accordingly. The syllogism, therefore, is essentially 
an instrument of proof and of thought organization, not a 
mode of ordinary thinking. 

Deduction and Induction. — The logician divides thinking 
into two forms, deduction and induction. The former proceeds 
from the general to the particular, being the subsumption of 
particular instances under established general principles. The 
syllogism is its type. Inductive thinking proceeds from particu- 
lar to general, consisting in the formation or establishment of 
general principles. Concept formation is a typical case. The 
concept "mortal man" is built up from a large array of experi- 
ences with men each of whom has proved mortal — a process of 
induction, which may also be termed one of habit-formation. 
Once the habit or concept is formed, I proceed to apply it to 
specific cases. Each man is classified or interpreted as mortal 
— a process of deduction and also a process of habitual response. 
Both activities are constantly and simultaneously present in 
the organism, for each conscious state and each motor response 
is alike a case affecting habit-formation and a case of the appli- 
cation of a habit already formed. 

This last point may well bring our account of thinking to 
a close. In the process of thought the organism has its most 
variable and plastic means of adjustment, a process that cannot 
be distinguished from a sequence of habits and instincts inte- 
grated toward a given end plus the conscious concomitants of 
such a sequence. Thinking, however, is to be set off from an 
instinctive sequence by virtue of the fact that it is not deter- 
mined chiefly by heredity. We can regard instinct as the con- 
servative racial solution for problems that arise, and thinking 



THINKING 341 

chiefly as the individual's own contribution toward his preser- 
vation. 

The "individual" of whom we speak, let it be remembered, 
is a most complex organism certain to have its relative place 
in the population on the basis of its mental ability; certain also 
to retain traces of its infrahuman ancestry and of its life with 
other individuals of its kind; and, because of the complicated 
environment in which it lives, certain to be subject to abnor- 
malities and disease. This individual, the subject-matter of 
psychology, is not a cold and abstract entity, but is nothing 
less than that fascinating friend, the human nature in each of us. 



REFERENCES 

Ach, N. Ueber die Willenstatigkeit und das Denken. Gottingen: 
1905. 

Angell, James R. Psychology, chaps x-xii. Fourth edition. New 

York: 1908. 

. "Imageless Thought," Psych. Rev., XVIII (191 1), 295 ff. 

Binet, A. L 'Etude experimentale de V intelligence. Paris: 1903. 
Buehler, K. " Ueber Gedanken," Arch. f. d. ges. Psych., IX (1907), 

297 ff. 
Dewey, John. How We Think. Boston: 19 10. 
Marbe, K. Exper. -psych. Untersuchungen ueber das Urteil. Leipzig: 

1901. 
Martin, L. J., and Mueller, G. E. Zur Analyse der Unlerschiedsem- 

pfindlichkeit. Leipzig: 1899. ' 
Also reviewed by F. Angell, Amer. Jour. Psych., XI (1899- 

1900), 266-71. 
Mill, James. Analysis of the Phenomena of the Human Mind. 

London: 1829. 
Pillsbury, W. B. The Psychology of Reasoning. New York: 1910. 
Titchener, E. B. Experimental Psychology of the Thought Processes. 

New York: 1909. 



342 GENERAL PSYCHOLOGY 

Watt, H. J. "Exper. Beitrage zu einer Theorie d. Denkens," Arch. 

f. d. ges. Psych., IV (1905), 289 ff. 
Whipple, G. M. "An Analytic Study of the Memory Image and the 

Process of Judgment in the Discrimination of Clangs and Tones, " 

Amer. Jour. Psych., XII (1901), 409 ff ; and XIII (1902), 219 ff. 
Woodworth, R. S. "The Consciousness of Relation," Essays in 

Honor of William James, pp. 483-507. New York: 1908. 
. "A Revision of Imageless Thought," Psych. Rev., XXII 

(1915), 1-27. 



INDEXES 



AUTHOR INDEX 



Ach, N., 320, 328, 341 

Adams, H. F., 59, 60 

Adler, A., 83 

Ames, E. S., 109 

Angell, F., 341 

Angell, J. R., 9, 125, 131, 199, 206, 211, 214, 
272, 276, 280, 292, 318. 341 

Aristotle, 285 

Arnsohn, E., 229 

Austen, J., 290 

Bain, A., 191, 199 

Bair, J. H., 305 

Baird, J. W., 276 

Baldwin, B., 109 

Baldwin, J. M., 91, 99, 109, 174 

Barber, A. G., 18 

Bechterew, W. von, 16 

Bentley, I. M., 109 

Bergson, H., 282 

Berkley, G., 221 

Bernoulli, A. L., 16 

Bernstein. 270 

Berry, C. S., 30 

Betts, G. H., 280, 292 

Billings, M. L., 131 

Binet, A., 3, 38, 328, 341 

Bing, R., 157 

Bingham, W. V., 276 

Bjerre, P., 64 

Bloomfield, D., 22, 168, 178 

Boas, F., 106, 109 

Book, W. F., 318 

Boring, E. G., 235, 237, 239 

Breed, F. S., 22, 166, 167, 177, 178 

Breese, B. B., 9 

Breuer, J., 79 

Bridges, J. W., 60 

Brown, T., 191, 199 

Bryan, W. L., 315, 318 

Buehler, K., 328, 334, 341 

Calkins, M. W., 276, 290, 293, 299 
Cannon, W. B., 186, 199, 236, 239 
Carlson, A. J., 237, 239 
Carr, H. A., 34, 239, 256, 313, 318 



Charcot, J. M., 3, 81, 280 
Chaucer, G., 197 
Church, A., 69 
Clark, Helen, 109 
Conradi, E., 168, 177 
Cope, E. D., 173 

Darwin, C, 3, 14, 15, 189, 199, 333 
Davenport, C. E., 60 
Descartes, R., 281 
De Voss, J. C, 28 
Dewey, J., 336, 330, 34i 
Dunlap, K., 9, 157 

Ebbinghaus, H., 266, 278, 297, 299, 303, 
312, 318 

Ellis, H., 83, 214 

Ellwood, C. A., 85, no 

Fechner, Th., 3, 266 
Ferguson, G. O., Jr., 109, no 
Fernald, Mabel, 280, 293 
Fernberger, S. W., 214 
Ferree, C. E., 131, 257 
Fite, W., 272 
Franz S. I., 235 
Freud, S., 54, 66, 79, 83 
Frey, M. von, 270 

Gall, F. J., 152 
Galton, F., 16, 279, 293 
Gamble, E. Mc, 131 
Ganson, R., 28 
Giddings, F. H., 89 
Goddard, H. H., 41, 48, 50. 60 
Goldscheider, A., 232 
Gordon, K., 214 

Haggerty, M. E., 30, 34 

Haines, T. H, 83 

Hamilton, Sir William, 122 

Hardesty, I., 245, 276 

Hardwick, R. S., 60 

Harter, N., 315, 318 

Hartley, D., 285 

Head, H., 148, 188, 199, 235, 239 

Healy, W., 41 



345 



346 



GENERAL PSYCHOLOGY 



Helmholtz, H. von, 3, 241, 244, 248, 261, 
274, 276 

Herbart, J. F., 208, 218 

Hering, E., 3, 261 

Herrick, G. J., 148, 157, 214, 239 

Hess, C, 25 

Hobbes, T., 86 

Hobhouse, L. T., 30 

Hocart, A. M., 107, no 

Hollingworth, H. L., 59, 60 

Hobnes G., 148, 188, 199 

Holt, E. B., 171 

Howell, W. H., 157 

Hume, D., 285, 287 

Hunter, W. S., 18, 30, 33, 34, 293, 304 

James, William, 9, 96, 99, 166, 177, 180, 187, 

199, 217, 239, 282, 290, 293, 339 
Janet, P., 3, 73, 76, 83 
Jelliffe, S. E., 66, 83 
Jennings, H. S., 34 
Johnson, H. M., 18, 25, 34 
Jones, E., 83 
Jost, A., 309 

Klemm, Otto, 9 
Koenig, R., 259 
Krafft-Ebing, F. R. von, 71 
Kries, J. von, 259 
Kriiger, F., 248 
Kuhlman, F., 41 

Ladd, G. T., 214, 276, 318 

Lange, K., 180, 199 

Lashley, K. S., 25, 27, 35, 178, 308 

Le Conte, J. L., 276 

Lee, Vernon, 199 

Leuba, J. H., no 

Lickley, J. D., 157 

Locke, J., 281 

Lotze, R. H., 270 

McComas, H. C, 131 

McDougall, W., no, 171, 177, 191, 194, 199 

Marbe, K M 328, 333, 341 

Marshall, H. R., 17s 

Martin, L. J., 328, 341 

Mayo, M. J., 109, no 

Meumann, E., 307, 319 

Mill, J., 285, 325, 341 

Moll, A., 83 

Moore, H. T., 276 

Morgan, C. L., 14, 15, 166, 174 

Miiller, G. E., 263, 266, 299, 306, 328, 341 



Miiller, J., 264 

Mtinsterberg, H., 8, 9, 58, 60, 305 

Myers, C. S., 175, 319 

Osborne, H. F., 174 

Parker, G. H., 16, 228 

Parsons, J. H., 276 

Paterson, D. G., 41, 60 

Pawlow, J. P., 16, 186 

Pearce, B., 304 

Pechstein, L. A., 308 

Peterson, F., 69 

Peterson, J., 276, 319 

Pierce, A. H., 276 

Pillsbury, W. B., 131, 293, 319, 341 

Pilzecker, A., 299 

Pintner, R., 41, 60 

Prince, M., 73, 83 

Pyle, W. H., 109 

Radossawljewitsch, P., 301, 312 

Rahn, C., 148 

Rand, G., 257, 276 

Reid, T., 221 

Ribot, Th , 171, 191, 192, 199 

Rivers, W. H. R., 235, 239 

Romanes, G. J., 3, 14, 15 

Ross, E. A., 95, no 

Rousseau, E., 86 

Ruskin, J., 195 

Schumann, F., 328 
Scott, W. D., 59, 60 
Scott, W. E. D., 168, 177 
Seashore, C. E., 60 
Segal, J., 280 

Shambaugh, G. E., 245, 276 
Shand, A., 197, 199 
Shepard, J. F., 22, 131, 167, 178, 211 
Sherren, J., 239 

Sherrington, C. S., 161, 177, 185, 199, 222 
Simon, Th., 38 
Spalding, D. A., 166 
Spencer H., 3, 173 
Spurtzheim, G., 152 
•Stabler, E. M., 228 
Steffens, L., 307 
Stern, W., 41, 44, 60, 119 
Stevens, H. C., 131 
Stevenson, R. L., 73 
Stout, G. F., 9 
Stratton, G. M., 9 



AUTHOR INDEX 



347 



Strong, C. A., g 
Strong, E. K., 59 
Stumpf, C, 248 
Sylvester, R., 41 

Tarde, G., 91, no 

Terman, L. M., 41, 44, 47, 60 

Thompson, C. A., 199 

Thorndike, E. L., 30, 35, 60, 93, no, 166, 

178, 313,319 
Titchener, E. B., 9, 131, 194, 199, 205, 214, 

222, 239, 276, 293, 341 

Ulrich, J. L., 29, 35, 308 

Walter, H. E., 60 

Walton, A. C, 33 

Washburn, M. F., 35 

Watson, J. B., 15, 16, 24, 25, 30, 34, 35, 178, 
312,313,319 

Watt, H. J., 276, 319, 320, 328, 335, 342 

Weber, E., 3, 265, 270 



Wetterstrand, G. O., 81 

Whipple, G. M., 60, 328, 330, 342 

White, W. A., 66, 83 

Whitman, C. O., 174 

Witasek, S., 307 

Witchell, C. A., 168 

Woodrow, H. S., 131 

Wood worth, ,R. S., no, 214, 276, 318, 328, 

334, 342 
Woolbert, C. H., 109 
Wundt, W., 3, no, 173, 201, 205, 211, 214 
Wylie, H. H., 30, 319 

Yarbrough, J, U., 33, 304 

Yerkes, R. M., 9, 22, 25, 26, 30, 35, 41, 44, 
60, 141, 168, 178 

Yoakum, C. S., 35 

Zeliony, G. P., 18 
Zenneck, J., 16 
Zwaardemaker, H., 229 



SUBJECT INDEX 



Abnormal psychology: problems of, 61 f. 
structural psychoses in, 62, 67, 68 f. 
functional psychoses in, 62, 67, 73 
defense mechanisms, 62 ff., 71; types of 
mental disease, 66 f.; causes of nervous 
and mental disease, 67 f.; paresis, 68 ff.; 
paranoia, 70 ff.; multiple personality, 
72 ff.; hysteria according to Janet, 76 ff.; 
hysteria according to Freud, 79; Freud's 
conception of the neuroses, 79 f.; psycho- 
analysis, 79 ff.; hypnotism, 81 f.; dreams, 
82 

Absolute impression, 329 f. 

Accommodation: in attention, 129; in 
vision, 274 

Advertising, 59 

Aesthesiometer, Fig. 51 

Aesthetic emotion, 194 f., 209 f. 

Affective processes: neural basis of, 148, 
188 f., 205, 210 f.; qualities of, 200 ff.; 
and emotion, 201; attention to, 202 f.; 
location of, 203; meaning, 203 f.; com- 
pared with sensation, 204 ff.; stimuli 
for, 208 ff.; bodily changes in, 211; 
memory of, 212 f.; function of, 213 f.; 
and habit-formation, 213 f., 314 

After-images, 255 f. 

Anger, 192 f., 201 

Animal psychology: objective point of 
view in, 13 f.; consciousness in, 13 f.; 
chief problems of, 14 f.; learning, 14, 
22 f., 28 ff.; results of, 15; method of 
field observation in, 15 f.; method of 
general response in, 16 f.; method of 
selective response in, 18; hearing, 16, 18; 
conditioned reflex, 16 ff., 160; tropisms, 
19 ff.; instinct, 21 f.; kinaesthetic sensi- 
tivity, 22 ff.; organic sensitivity, 22 ff.; 
use of maze in, 22 ff.; color-vision, 25 ff.; 
imitation in, 30 f., see Social Psychology, 
91 ff.; delayed reaction, 31 ff.; idea, 33; 
intelligence, 34; instinct in birds, 165 ff.; 
emotional disturbances in dogs and cats, 
185 ff.; see Reflex Action, Instinct, 
Learning, and Memory 

Aphasia, 154 

Apperception, 217 f. 

Applied psychology: nature of, 53; in 

medicine, 54 f.; in law, 55 f.; in education, 

56 f.; in business, 57 ff. 
Association: dissociation, 61, 76 f., 81; 

free association, see Psychoanalysis; 

as condition of attention, 119; laws of, 

285 ff.; neural basis of, 286 f.; total and 



focalized recall, 290; simultaneous, 291 f.; 
remote, 302; see Learning and Memory 

Attention: selection in, 113 f.; as clearness, 
113 f.; anatomical conditions of, 114 f.; 
objective conditions of, 115 f.; subjective 
conditions of, 117 f.; accuracy of, 119 ff.; 
Aufgabe in, 121; scope of, 122 ff.; divided, 
124, duration and fluctuation of, 1242.; 
Traube-Hering waves in, 126 f.; classes of, 
127 f.; motor accompaniments, 128 ff.; 
and affective processes, 202 f. 

Audition: in animals, 16; classes, 240; 
stimuli and receptors, 240 ff.; theories of, 
244 f.; harmony in, 245 f., 248 f.; beats, 
246 if.; difference tones, 247 f.; auditory- 
space, 290 ff. 

Aufgabe: in relation to attention, 121; in 
thinking, 335 

Axis cylinder, 136 f. 

Axone, 133 f., 136 

Basilar membrane, 244 
Beats, 246 f. 

Behavior: definition of, 4L; organic, 
5, 14; in Social Psychology, 85 

Belief, 215 f., 278 

Birds: color-vision in, 27; vocalization in, 

168 f. 
Blind spot, 250 

Campimeter, Fig. 49 

Cats: color-vision in, 28; delayed reaction 

in, 31 f.; emotional disturbances in, 

186 ff. 
Cerebellum, 147 

Cerebro-spinal nervous system, 141 f. 
Cerebrum, see Cortex 
Chicks, pecking in, 166 f. 
Chromatin, 135 
Circulation: changes in blood pressure, 

126 f., 129 f.; nervous control, 144, 146; 

in emotion, 179, 187; in affection, 211 
Clearness: as attention, 113 f.J in affective 

processes, 202 f.; in sensation, 216 

Cochlea, 241 f. 

Cold, see Cutaneous Sensitivity 
Color-blindness, 258 ff. 
Color-mixture, 254 
Color-pyramid, Fig. 48 
Compensation, 207, 229 



348 



SUBJECT INDEX 



349 



Complementary colors, 254 f. 

Concept: nature of, 320 f.; formation of, 
322 ff.; values and limitations of, 324 ff. 

Consciousness: nature of, 5; relation to 
nervous system, 5, 21, 132, 148 ff.; 
in Social Psychology, 85; in fluctuations of 
attention, 125 f. 

Consonance, see Harmony 

Corpora quadrigemina, 147 

Corpus striatum, 148 

Cortex, cerebral, 148 ff. 

Cranial nerves, 154 

Curves of learning, 24, 167, 314 ff. 

Custom: in relation to instinct, 88 f.; 
nature of, 101 f . 

Cutaneous sensitivity: neural basis^ of, 
230 f.; distribution of, 232 f.; stimuli for, 
233 f-J pain, 234; epicritic, protopathic, 
and deep sensitivity, 235; space, 268 f. 

Deduction, 340 f . 

Deep sensitivity, 235 

Defense mechanisms, 62 ff., 71 

Delayed reaction, 31 ff. 

Dendrites, 133, 136 

Difference-tones, 247 f. 

Dissociation, see Association 

Dogs: delayed reaction in, 31 f.; emotional 

disturbances in, 185 f. 
Dreams, 82 

Educational psychology, 56 f. 

Effector, 133, 138, 173 

Effort, 128 

Emotion: in relation to sympathy, 89 ff.; 
in relation to the self, 100; and attention, 
120; and sympathetic nervous system, 
144, 187; neural basis of, 148, 185 f.; 
James-Lange theory of, 179 ff.; criticisms 
of James-Lange theory of, 179 ff.; and 
instinct, 179, 186, 189, 198; and affective 
processes, 183, 201; in dogs, 185 f.; 
in cats, 186 ff.; expressions of, 189 f.; 
classification of, 190 f.; simple and 
complex, 191 ff.; the tender emotion, 
191 f.; fear, 192; anger, 192 f.; scorn, 
193 f.; aesthetic, 194 f.; empathy, 194 f.; 
mood, 196; temperament, 196; sentiment, 
196 ff.; function of, 198; memory for, 286 

Empathy, 194 f. 

Epicritic sensitivity, 235 

Equilibrium, 147, 242; see Tabes 

Extero-ceptors, 223 

Eye, 250 f. 

Facilitation, 129, 159, 161 ff. 
Fatigue, 135 
Fear, 62 ff., 192 



Feeble-minded, 37, 45, 47 ff., 66 
Fixation of arcs in habit, 312 ff. 

Forgetting: as defense mechanism, 64 f.; 
in hysteria, 7g; and psychoanalytic 
method, 80 f.; nature of, 310 ff.; rate of, 
312 

Fovea, 250 

Fusion, 207, 230 

General intelligence, 34, 50 f., 56, 68, 105 ff., 

139, 17s f- 
Genius, 37, 45 

Habit, see Learning 

Harmony: stimulus for emotion, 194 f.; 
in audition, 245 f., 248 f. 

Hate, see Sentiment 
Hunger, 237 f. 
Hypnotism, 81 f. 
Hysteria, 76 ff. 

Idea: in animals, 33; in thinking, 331 f.; 

see Concept 
Induction, 340 f. 

Image: and sensation, 277 f., 284 f. 
neural basis of, 279; types of, 279 f. 
productive and reproductive, 281 f. 
function of, 282 f.; sequence of, 284 f. 
simultaneous association, 291 f.; and 
memory, 295 f.; in thinking, 331 ff. 

Imageless thought, 333 ff. 
Imitation: in animals, 30 f.; in Social 
Psychology, 91 ff.; as an instinct, 92 f. 

Individual psychology: nature of, 36 f.; 
feeble-minded, 37, 45, 47 ff.; genius, 37, 
45; special ability tests, 37, 55, 576.; 
Binet-Simon tests, 37 ff.; criticisms of 
Binet scale, 40 ff.; mental age, 40 f., 
44 f.; performance tests, 41 f.; intelli- 
gence quotient, 44 f.; group tests, 46; 
Yerkes' point scale, 46; inheritance of 
general intelligence, 50 f., 68; statistical 
method in, 51 f. 

Inhibition, 129, 159, 161 ff. 

Instinct: permanency of, 80 f., 88, 169 f.; 
in society, 86 ff.; and imitation, 92 f.; 
as condition of attention, 117 f.; neural 
basis of, 139; and reflex action, 163 f. 
definition of, 163 f.; criteria of, 164 f. 
experimental studies of, 165 ff., 185 ff. 
modifications of 166 ff., 170 f.; origin of 
171 f., 189 f.; classification of, 174 f. 
and intelligence, 175 f.; and habit, 176 f 
and emotion, 179, 186, 189, 198 

Intelligence quotient, 44 f. 

Intero-ceptors, 223 

Introspection, nature of, 7 

James-Lange theory of emotion, 179 ff. 

Judgment: nature of, 327 f.; experimental 
studies of, 328 f.; role of image in, 331 ff.. 



35° 



GENERAL PSYCHOLOGY 



Kinaesthetic sensitivity: in animals, 22 ff.; 
in tabes, 146; as sensation, 235 ff. 

Krause, end-organ of, 231 

Kymograph Fig. 18 

Language: in relation to intelligence, 106 ff.; 
as condition of attention, 118; in habit, 
300, 302 f. 

Learning: in animals, 14, 22 f., 28 ff.; 
under social conditions, 87 f.; as condition 
of attention, 118; neuraTbasis, 139, 312 ff.; 
in worms, 141; in chicks, 166 f.; in birds, 
168 f.; and reflexes and instincts, 176 f.; 
and affective processes, 217 f.; habit- 
interference in, 304 f.; transfer of training 
in, 305; economical method of, 309. 

Localization of function, 151 ff. 

Locomotor ataxia, see Tabes 

Love, see Sentiment 

Maze, used with animals, 22 ff.; habits in 
worm, 141 

Meaning: in attention, 123; neural basis of , 
148; in affective processes, 203 f.; in 
sensation, 216, 220 f.; general, 320 ff. 

Medulla, 141 f. 

Medullary sheath, 136 

Meissner corpuscle, 231 

Melody: stimulus for emotion, 194; in 
audition, 245 f. 

Memory: for affective processes, 212 f.; for 
emotion, 286; definition of, 294; and 
images, 295 f.; recognition, 2962.; experi- 
mental studies of, 297 f.; problems of 
retention, 298 ff.; significant versus 
nonsense material, 301; remote associa- 
tion, 302; interference in, 304 f.; transfer 
of training in, 305; practice and intention 
in, 305 f.; whole and part method in, 
307; distribution of effort in, 308; 
training and economy of, 309 f .; forgetting 
in, 310 ff.; fixation of arcs in, 312 ff.; 
curves of learning in, 314 ff.; function of, 
3i7 f- 

Mendel's law, 172 

Mental age, 40, 44 f. 

Mental disease: and development of self, 
97 ff.; see Abnormal Psychology 

Mental survey, 46 

Mob, 103 f. 

Mood, 196 

Multiple personality, 72 ff. 

Nerve center, 146 

Nervous system: relation to consciousness, 
5, 132; development of, 20, 139 ff.; 
reasons for study, 132; as psychological 
study, 133; the neurone, 133 f.; function of, 
i33> 138; reflex arc, 138 f.; divisions of, 
141 .; spinal cord, 144 f.; and emo- 
tion, 148, 188 f.; medulla, 146 f.; cere- 



\ 

bellum, 147; mid-brain, 147; thalamus, 
147 f.; corpus striatum, 148; cerebral 
cortex, 148 f.; cranial nerves, 154; con- 
duction paths, 154 f.; localization of 
function, 155 ff. 

Neurilemma, 137 

Neurofibrils, 135 

Neurone, 133 f. 

Noise, 240 f . 

Nonsense syllables, 297 

Objective point of view, see Animal Psy- 
chology 
Olfactometer, Fig. 38 
Optic disc, 250 

Organic sensitivity: in animals, 22 f.; 
and emotions, 180 ff.; in sensory pro- 
cesses, 235 ff. 

Pacinian corpuscle, 231 
Pain: in reflex action, 163; in defense 
mechanisms, 164; in sensation, 234 

Paranoia, 70 ff. 

Paresis, 68 ff. 

Perceptiorij^rTJ. 

Peripheral color-vision, 256 f 

Physiological zero, 233 

Pitch, 241 

Plethysmograph, 131 

Pneumograph, Fig. 18 

Pressure, see Cutaneous Sensitivity 

Proprio-ceptors , 222 

Protopathic sensitivity, 235 

Psychoanalysis, 79 ff., 288 

Psychology: general goal of, 3; historical 

beginnings of, 3; subject-matter of, 4ff.; 

methods of, 5 ff.; fields of, 7 f.; see 

Animal, Individual, Abnormal, Social, 

and Racial 
Psychotechnique, 8 
Purkinje phenomenon, 27, 261 

Racial psychology: problems of, 104 f.; 
racial differences in general ability, 
105 ff.; mental tests in, 108 f. 

Receptor, 133, 138, 173, 227, 231, 241 f., 
242, 250 f. 

Recognition, 296 ff. 

Reflex action: conditioned reflexes, 16 ff., 
160; and instinct, 103 ff.; neural basis of, 
154 ff.; definition of, 158 f.; and tro- 
pisms 159; types of, 160 f.; scratch re- 
flex, 161 ff.; phenomena of, 161 f.; and 
habit, 176 f. 

Reflex arc, 138 f., 159; see Fixation of 
Arcs 

Respiration: changes in attention, 127, 
129 f.; nervous control, 146; in affection, 
211 



SUBJECT INDEX 



351 



Retention, 298 ff. 
Retina, 250 
Rivalry, 207, 230 
Rolando, fissure of, 155 
Ruffini, end-organ of, 231 

Saccule, 242 

Scorn, 193 f. 

Self: in multiple personality, 72 ff.; rela- 
tion to instincts, 87 ff.; socializing influ- 
ences, 895,; nature of, 96 f.; develop- 
ment of, 97 f.; Baldwin on the growth of, 
99 f- 

Semicircular canals, 242 f. 

Sense-organs: origin of, 20; as conditions of 
attention, 113; see Receptor. 

Sensory processes: definition of, 215; 
and perception, 217 f.; and apperception, 
217 f.; development of, 218 f.; and 
meaning, 220 f.; classification of, 221 ff.; 
taste, 225 ff.; smell, 227 ff.; cutaneous sen- 
sitivity, 230 ff.; kinaesthetic and organic, 
235 ff.; audition, 240 ff.; vision, 255 ff.; 
specific nervous energy, 263 f.; Weber's 
law, 265 f.; awareness of space, 267 ff.; 
tactual space, 268 ff.; auditory space, 
270 ff.; visual space, 272 ff.; functions of, 
274!; and images, 277 f., 284^; sequences 
of, 284 f.; simultaneous association and, 
291 f. 

Sentiment, 196 ff. 

Smell: neural basis of, 227; stimulus for, 228 

Social psychology: general problems of, 84; 
society, 85 f.; place of instincts in, 86 ff.; 
the self as social, 87 ff.; socializing in- 
fluences, 89 ff.; social institutions, 100 ff.; 
nature of custom, 101 f.; the mob, 103 f. 

Society, 85 f. 

Sound cage, fig. 52 

Space: location of affective processes in, 
203; awareness of, 267 ff.; tactual, 268 ff.; 
auditory, 270 ff.; visual, 272 ff. 

Specific nervous energy, 263 f. 

Spinal cord, 144 f. 

Statistical method, 51 f. 

Suggestion, 94 ff. 



Syllogism, 338 f. 

Sympathetic nervous system, 141 f., 187 

Sympathy, 89 ff.; see Tender Emotion 

Synapse, 139, 159 

Syphilis: as cause of mental and nervous 

disease, 67; in paresis, 69; effect on 

spinal cord, Fig. 27. 

Tabes, 146 

Tachistoscope, Fig. 16 
Taste: qualities of, 225; as four senses, 
225 f.; neural basis of, 227 

Taste-buds, 227 

Tectorial membrane, 245 

Temperament, 196 

Tender emotion, 191 f. 

Testimony, in applied psychology, 55; 
in attention, 119 ff. 

Tests, see Individual and Racial Psychology 

Thalamus, 147 f. 

Thinking: definition of, 320, 332; concept 
in, 320 ff.; formation of concepts, 322 ff.; 
values and limitations of concepts, 324 ff.; 
the absolute impression, 324 f.; judgment, 
327 ff.; r61e of image in, 331 ff.; conscious 
attitude, 333 f.; the Aufgabe, 335; analy- 
sis of concrete act of, 335 ff.; place 
of syllogism in, 338 f.; deduction and 
induction, 340 f.; function of, 340 

Tropisms, 19 ff., 159 

Twilight vision, 260 f. 

Utricle, 242 

Vision: color-vision in animals, 25 ff.; 
and space-discrimination, 223, 272 ff.; 
receptors for, 250 f.; qualities of, 252 f.; 
color-mixture, 254; complementary 
colors, 254 f.; simultaneous contrast, 
255 f.; after-images, 255 f.; peripheral 
color- vision, 256 f.; color-blindness, 258 ff.; 
twilight vision, 260 f.; theories of, 261 ff.; 
visual space, 272 ff. 

Warm, see Cutaneous Sensitivity 
Weber's law, 265 f. 



